Similar to rising interest rates, consumer and producer prices have

ajit257,

Good question. "As" in the context in which you are asking has to do with comparisons. Notice how the question substitutes "similar to" and "like" for "as" in the different answer choices. On the GMAT, "like" and "as" serve different purposes. (People very often use these wrong in speech, so be careful):


Like: Used to compare nouns
As: Used to compare clauses (clauses contain verbs)

"My uncle looks like my aunt." --> Correct: We're saying the two look SIMILAR TO each other. One noun (my uncle) is similar to another noun (my aunt).

"My uncle looks at me as my aunt does."--> Correct: We're saying they both look at me in a similar way. They both DO things in a similar way, so we're no longer comparing nouns and thus can't use "like."

"My uncle looks as my aunt." --> Incorrect. "My aunt" is a noun and and needs to be compared using "like."
"My uncle looks at me like my aunt does." --> Incorrect because we're comparing two clauses (how my uncle looks at me and how my aunt looks at me) and thus we need to use "as" instead of "like."

The question you want to ask yourself, then, is: "What is being compared to what?" If you're comparing nouns, use "like." If you're comparing clauses, use "as."

This all helps explain some of the wrong answers.

The next thing to notice here is that comparisons (which use "like" or "as") require parallel construction. If you look at a few of these answer choices, you see broken parallelism:

As (present tense), so (present perfect tense).
As (present perfect tense), so (present tense).

So we can also narrow down answer choices this way. Why don't you use this to take a guess and see how you do? I'll be notified when you respond.

Brett