If the depletion of the ozone in the upper portion of the Earth's atmo

When you say 'would be at least one thousand miles wide', the "or wider" is assumed. Including "or wider" would be redundant.

The first thing we could notice easily is “if” Clause/Conditional. In an Unreal conditional sentence, if the verb in the “if” clause is ‘to be’, we use ‘were’, even if the subject of the clause is a third person singular subject(he,she,it). Eliminate C and E.
‘At least one thousand miles wide’ is the correct form. Eliminate A.
In D, past continuous form is used in ‘if’ clause(were continuing...). Wrong.
B is correct.

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As rodri102 mentioned, the or wider is redundant. For example:

You asked for at least two cookies.

The at least itself makes it clear that you asked for 2 or more cookies, so you don't have to put an or more in the sentence.

3 of our answer choices have unnecessary redundancy in the form of "at least" & "wide or wider".

This leaves us with B and D.
D has a glaring mistake: "if... were continuing"

Hence B is the winner by method of elimination.

Hi,

Why is were used here, subject is depletion which is singular.

The sentence is about a hypothetical situation. So, it's correct to use the subjunctive "were" rather than the indicative "was."

Something about conditionals.

TYPE 0 CONDITIONALS
If(or when) + present tense | present tense
If(or when) + past tense | past tense

If and when can be interchangeably used only when we are talking about situations that are definitely going to happen.
If a situation is dependent on something, then we use "if".

If it rains, I won't go out. correct
When it rains, I won't go out. Wrong

If you heat water it evaporates. correct
When you heat water it evaporates. correct

Remember, Type 0 is the only conditional type in which you can use "if" and "when" interchangeably.

TYPE 1 CONDITIONAL (Things are likely to happen here)
The type 1 conditional expresses a future scenario that might occur. Assuming that the condition is fulfilled, the outcome is likely to happen.

If + present tense | will (may/might/can/could/should) + verb

If I get paid, I will go shopping.
If I see that man, I may say something.

TYPE 2 CONDITIONAL (Things are unlikely to happen here)
This can either refer to future hypotheticals that are unlikely to be true or present situations that are untrue or impossible.

If + simple past | would

If I were president, I would rule.
If I were rich, I would travel the world.
If I were invisible, I would rob the bank.

TYPE 3 CONDITIONALS
The unreal situation in the past, with reference to the hypothetical outcome that would result also in the past.

If + past perfect | conditional perfect

If I had known you were going to react, I would have not done that.

If you had seen the movie, I would have/could have taken you out to watch its sequel.

Hello ArpitJain1997ew,

We hope this finds you well.

To answer your query, since the verb "were" refers to a hypothetical action, the use of the subjunctive mood is preferred; “wishful trigger (if) + plural form of verb” is a correct, subjunctive usage; example: "If I were an athlete, I would be super fit.".

In an imaginative context, subjunctive mood is a preferred usage for conveying the intended meaning effectively.

To understand the concept of "Subjunctive Mood" on GMAT, you may want to watch the following video (~20 minutes):



All the best!
Experts' Global Team

Option B does not even have a 'if' in the sentence. But the structure is similar to a if..then caluse. Is it correct to start a sentence with 'were' in the manner option does

As " depletion of ozone layer " should be considered as singular , using " were" must be wrong , hence i eliminated all the sentence that used "were".
kindly comment

GMATNinja AjiteshArun KarishmaB

Is omitting 'if' in unreal condition is fine sometimes? as 'if' is omitted in answer choice 'B'?

Hi Akhilshah,

There are structures in which we don't see an if.

1. Were with inversion

Were he the author, I would have asked for an autograph. ← No if, and were is before the subject. This is like saying "If he were the author...".

2. Were + to with inversion

Were he to sign a copy of the book... ← No if, and were is before the subject, followed by an infinitive (to sign). This is like saying "If he were to sign a copy of the book...".

We can also use the verbs had and should.

3. Had he answered the last question... ← This is like saying "If he had answered the last question...".

4. Should you change your mind... ← This is like saying "If you change your mind...".

AjiteshArun Thank you! That's helpful!