This is GMATPREP question

If current trends continue, by the year 2010 carbon emissions in the United States will soar to a level more than one-third higher than were those in 1990, according to official projections.
A. will soar to a level more than one-third higher than were those
B. will soar to a level more than one-third higher than that
C. would soar to a level more than one-third higher than is was
D. would soar to a level more than one-third higher than those
E. would soar to a level more than one-third higher than they were

I chose E. So what is wrong with answer "E"? What is the correct answer. How to decide between will and would.Thanks

I chose D over E. not E because we are comparing levels of carbon emissions in US, not US to another country. So when comparing one of X to another of X, those is appropriate

Do you know what is error in "A" . Also OA is "B". So Why B is correct and others are wrong.

Here the rule of if clause


real condition

if < present tense> , then clause < future tense or present>

Here would is wrong that comes '

Hypothetical if < were >, then would ....

if < had been> , then would + present perfect

so C D and E rules out.

Now A is wrong as those can to refer carbon emissions or current trends that is illogical ; B is correct captures the meaning " that refers to a level"

you need 'will', not 'would'. 'would' is used if the hypothetical is in the past tense, while 'will' (future tense) is used if the hypothetical is in the present tense (as is the case here).
compare: if you tell that joke again, i will punch you.
that takes care of the last three answer choices.

as far as deciding a vs. b, just look at the pronoun that/those: it refers to the singular noun level. therefore, you must choose that, which is singular, so b > a.

also, the presence of a verb in choice a creates bad parallelism, because 'a level' does not have a verb. the two parts of the comparison must have the same grammatical structure; if the initial part (a level) doesn't have a verb, the second part can't have one either.