In the Amazon, the alignment of a fertile ecosystem and isolation from

In the Amazon, the alignment of a fertile ecosystem and isolation from other ecologies during early geological epochs has given rise to a great diversity of species, which, in many genuses, outnumber those is other regions on earth by 100 to 1.

A) isolation from other ecologies during early geological epochs has given rise to a great diversity of species, which, in many genuses, outnumber
--> correct.

B) isolation from other ecologies during early geological epochs has given rise to a great diversity of species, which, in many genuses, outnumbered

C) of isolation from other ecologies during early geological epochs have given rise to a great diversity of species that, in many genuses, outnumbered

D) of both isolation from other ecologies during early geological epochs have given rise to a great diversity of species that, in many genuses, outnumber

E) of isolation from other ecologies during early geological epochs has given rise to a great diversity of species that has, in many genuses, been outnumbering

Hi sayantanc2k, in E we have has been outnumbering which is complete. Can you recheck?

There seems to be a typo; it should be --- outnumber those in---- rather than - outnumber those is -. Outnumber those is doesn't make any logic.

how can alignment be the noun here? both alignment and isolation are noun connected with 'and'. Does they together not become plural?

A) isolation from other ecologies during early geological epochs has given rise to a great diversity of species, which, in many genuses, outnumber - correct

B) isolation from other ecologies during early geological epochs has given rise to a great diversity of species, which, in many genuses, outnumbered - "outnumbered" has the wrong tense. It should be consistent with the tense of "has given rise to"

C) of isolation from other ecologies during early geological epochs have given rise to a great diversity of species that, in many genuses, outnumbered - "outnumbered" has the wrong tense. It should be consistent with the tense of "has given rise to"

D) of both isolation from other ecologies during early geological epochs have given rise to a great diversity of species that, in many genuses, outnumber - "of both isolation" is wrong

E) of isolation from other ecologies during early geological epochs has given rise to a great diversity of species that has, in many genuses, been outnumbering - "of isolation" is wrong

It is talking about the alignment of two factors which resulted in a great diversity of species viz- 1. a fertile ecosystem 2. the fact that this ecosystem was isolated...epoch; hence alignment would be the subject and will take the singular verb.

Meaning analysis:
In Amazon, The alignment of
- a fertile ecosystem and
- isolation from other ecologies
during early geological epochs
has given rise to diversity of species,
(These species) which, in many geneses, outnumber those in other regions.

Error analysis:
There are two S-V pair and both agree with each other.
No idioms
Modifier Which clause is correctly modifying species.
Tense : No tense error because the intention of A is to say that these still outnumber and Everything is stated in present tense.

No Error.
So answer is A.

POE:

A) Correct
B) The use of HAS means we need the present tense "outnumber"
C) HAVE is incorrect
D) OF BOTH is incorrect
E) been outnumbering is incorrect, not sure what grammar rule E is violating, but "been outnumbering" sounds very wrong.

why is alignment the subject? shouldnt it be both alignment and isolation

Official Explanation

Creating a filter: when we read the sentence as written, an error may not leap out, so we can examine the answer choices.

Finding objective defects: we see a 2 versus 3 standoff between using the word "of" and not using "of" at the beginning of the answer. Checking back, both appear to be allowed by the sentence. So we look for more objective grounds to rule out answer choices. We have a lot of verb differences. "Has given" should be grammatically singular, since its grammatical subject is the singular "alignment." Ecosystem and isolation are nouns, but not subjects of the sentence, because they are locked within the prepositional phrase starting with "of." That rules out (C) and (D), which both use "have given." Then there's "outnumber." We are describing a generality, so the simple present tense is appropriate. That rules out (B) and (E).

The correct answer is (A).

what does alignment of isolation mean? the sentence uses gibberish language.

Posted from my mobile device

So what you actually mean is
The alignment of
presence of fertile ecosystem and
isolation from other ecologies.

written in this way, it is completely clear.

written in the original version is like: the coinsidence of my red sweater and absence of wind made me look funny. when, in fact, written correctly the sentence should say: the coinsidence of me wearing red sweater and the absence of wind.

Posted from my mobile device