The number of acres destroyed by wildfires, which have become an ongoi

The difference between due to and because of is as follows:

Due to is an adjective and needs a noun to refer to.
Because of is an adverb and needs a verb to refer to.

The game was stopped because of rain. Correct - because of referring to verb was stopped.
The stoppage was due to rain. Correct - due to referring to noun stoppage.
The game was stopped due to rain. wrong! - due to cannot refer to verb was stopped.

Similarly,

Wildfires have become threat due to drought. Wrong !... due to cannot refer to verb have become.
Wildfires have become threat because of drought. Correct - because of referring to verb have become.

Hence D is wrong. The OA given is correct.

+1 E

"The number" is singular. A and B out.
"wildfires" is plural. C out.
"Due to" means "caused by" or "resulting from". It would change the meaning.

The number of acres destroyed by wildfires, which have become an ongoing threat due to drought and booming population density, have increased dramatically over the past several years, prompting major concern among local politicians.

(A) have become an ongoing threat due to drought and booming population density, have increased

(B) have become an ongoing threat due to drought and booming population density, have been increasing

(C) has become an ongoing threat because of drought and booming population density, has increased

(D) have become an ongoing threat due to drought and booming population density, has increased

(E) have become an ongoing threat because of drought and booming population density, has increased

The core of the sentence is- the number of acres destroyed by wildfires has increased dramatically over the past several years.

As the subject of the sentence is “the number of acres”, we need to use the singular verb “has” and not “have”. Eliminate options A and B.

The relative pronoun “which” refers to the noun “wildfires”. Hence, we need to use the plural verb “have” instead of “has”. Eliminate option C.

Options D and E contain a difference in the idiomatic usage- “due to” and “because of”

“due to” connects two nouns whereas “because of” connects a clause with a noun.

Eg- The flight’s cancellation was due to bad weather. ( noun on either side)
The flight was canceled because of bad weather ( connects a clause with a noun)

In the given sentence, let’s look at what we have to connect-
Wildfires have become an ongoing threat (clause) due to/ because of drought and booming population density (noun)
As we have a clause on one side and a noun on the other side, we have to use the idiom “because of”

Option E is correct.

VP
GMAT SME
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Further to supplement the discussion go through this pdf - https://www.chompchomp.com/terms/subject.pdf

Also find time to read through this excellent articles:

• Subject-Verb Agreement + Pronouns from Narenn.
  
• Due to Vs Because of from e-GMAT.
  
• Due to Vs Because of – GMAT Verbal from e-GMAT.

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OFFICIAL EXPLANATION

A first glance at the answer choices indicates a choice between “have become" and “has become" at the start of the underline: plural vs. singular verbs. The end of the underline also has a have vs have issue with a different verb: “have increased” versus “has increased." While reading the original sentence for meaning, keep these differences in mind.

The subject of the original sentence is "the number of acres," which is singular. The main verb, however, is "have increased," which is plural. We need to find a choice that replaces "have" with "has." Moreover, the phrase "due to" is incorrect in this context. "Due to" is a phrase that must describe a noun. "The fire was due to drought" is correct, but "There was a fire due to drought" is not. When describing a verb phrase, "because of" is preferable: "There was a fire because of drought."

(A) This choice is incorrect as it repeats the original sentence.

(B) The plural verb "have been" does not agree with the singular subject "the number of acres." In addition, the phrase "due to drought . . ." is unidiomatic since "because of" (not "due to") should be used to modify the verb phrase "have become an ongoing threat."

(C) The modifier "which has become an ongoing threat . . ." contains the singular verb "has" which does not agree with the plural subject of the clause, "wildfires."

(D) The phrase "due to drought . . ." is unidiomatic since "because of" (not "due to") should be used to modify the verb phrase "have become an ongoing threat."

(E) CORRECT. The singular verb "has" agrees with the singular subject "the number of acres." Additionally, "because of drought . . ." is properly used to modify the verb phrase "have become an ongoing threat."
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The number of......singular and requires "has". So eliminate A and B

Which is modifying "wildfires". So needs "have" and eliminate C

Between D and E, E is correct (because of)

+1 for E.

First eliminator : "The number" is singular. So "has increased" is correct. Eliminate A and B.
Second eliminator: "wildfires" is plural, so the modifier phrase "which ....." should be plural. Eliminate C
Third eliminator: due is correct only if it can be replaced by "caused by".Because is more appropriate when a reason is given. Eliminate D

Hence Left with E

Crick

The original sentence has subject verb agreement error
The number of acres = singular subject
have = plural verb
Hence (A) and (B) are out
C is out because it uses a singular verb 'has' for plural subject 'wildfires'
D is out because it incorrectly uses used noun modifier 'due by' to modify the verb 'have become'

Hence E = CORRECT ANSWER

Another poor question/answer.

The answer should be D).
Due to clearly modifies the multiple noun "threats. We could as well replace "due to" with "caused by and the sentence is correct.

Please change the answer to (D).

IMO E is correct.

Alternate method to check is by asking the Question "Why".

"Because of " always answer "Why" : Why the wildfires have become threat ? because of drought.. It correctly modifies "have become"

Another example : " The ongoing threat is due to drought". Here, due to modifies threat and the usage is correct.

Moreover, "due to" is often preceded by the verb "to be".

Sayantan : Please correct me if I am wrong.

A.
Yes, being an adjective "due to" normally follows a linking verb, one that joins a noun with its adjective.

The girl is beautiful.
The cake tastes good.
You look tired.

However the only linking verb that seems to go with the adjective "due to" is the verb "to be".
Correct: The stoppage was due to rain.
Wrong: The cake tastes due to the cream. (This sentence is not correct since "due to" does not modify the noun "cake", but the verb "tastes".)

B.
The usage of "due to" can also be associated with "why", though the framed question may sometimes be awkward:

Why was the stoppage? (awkward)
The stoppage was due to rain.

Why was the delay? (not so awkward)
The delay was due to traffic jam.

Thanks a lot.

Is the due to not referring to the noun threat? Or maybe my basics are weak.

The sentence conveys the meaning that the action (verb) "becoming" was caused by drought and booming population density. Hence " because of " is required. The sentence answers the question:

Why has it become?
NOT Why is the threat?

In formal English, due to can be used only as an adjective, whereas because of can be used only as an adverb.

A handy way to distinguish is: If we remove the portion of the sentence starting with due to, the leftover sentence cannot stand on its own as complete sentence. In option D, if we apply this technique, the leftover sentence is:

The number of acres destroyed by wildfires, which have become an ongoing threat, has increased dramatically over the past several years, prompting major concern among local politicians.

This leftover sentence can stand on its own as complete sentence. Hence, the usage of due to is inappropriate here, making D an incorrect choice.

Our book EducationAisle Sentence Correction Nirvana discusses the distinction between due to Vs because of. Have attached the corresponding section of the book, for your reference.

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So I have a doubt, "the number of acres" portion. Aren't acres countable, so since the number of a countable noun would be plural, wouldn't it require the plural, have?

Or is the countable/non-countable debate only for "percent" (and not "number")? Appreciate the help in clearing my doubt!

Hello aa1411,

We hope this finds you well.

To answer your query, the "number" of a thing is always considered singular because it refers conceptually to how many of that thing there are. Logically, there can only be one answer to the question "What is the number of X thing?"; here, "number" refers to a numerical value, such as "1", "23", "8 and 3 quarters", and not to the things themselves.

We hope this helps.
All the best!
Experts' Global Team
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A and B gone for using have increased of have been increasing
C - which has is wrong as the which refers to the wildfires (plural)
Between D and E difference comes down to the use of due to and because of

So obvious choice here is E

I am a little confused with the "because of' part. How is the portion a verb here ? "Drought and booming population" are nouns, right ?

Rules for Because or Due to is a search away but GMAT prefers Because > Due to 90% times, so lets assume you dont have time and think of this - eliminate A, B, D
(A) have become an ongoing threat due to drought and booming population density, have increased
(B) have become an ongoing threat due to drought and booming population density, have been increasing
(D) have become an ongoing threat due to drought and booming population density, has increased


Althought The number is singular - which here is directed at Wildfires which is plural (or you can look at the split to do a double take instead of being stubborn about has) so C is out
(C) has become an ongoing threat because of drought and booming population density, has increased

Remaining E - right answer