Twenty years ago, only 6 percent of students at Dunmore College who in

Answer is A.

The intent of the sentence is to say that women majoring in chemistry at the school is at minimum 40%.

Also A has the proper structure as X as Y

Comparisons are being tested in this sentence .Look for the construction that makes the comparison as clear and correct as possible. This sentence compares the previous figure, or “6 percent,” with today’s figure, so you want something that is as similar in structure as possible to “6 percent.”
Scan and Group the Answer Choices
The comparison sounds good as is,
Reasons to Eliminate Choices :
(B) is awkward and redundant; it doesn’t make sense to have both “higher than” and “at least” next to each other. (C) changes the meaning of the sentence by saying “higher by 40 percent,” which means something different from “higher than 40 percent.” (D) introduces the awkward and confusing “40 percent high,” which is hard to decipher. Finally, (E) uses the egregious construction “more higher.”
So A it is.

C is not right because higher than and atleast together is redundant. When you say atleast, it itself means equal to or higher than a given quantity.

Thus, C won't be right in either of the cases.

Regards ?

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I can tell you what is wrong with other options out here. But would someone pls explain why A is correct or it is like we are only left with this best possible option out here ?

A. Looks to be only best possible option. Someone pls elaborate more.
B. Incorrect, Changes the meaning. This talk about increase in % figure itself, rather than original intended meaning of final increase to 40%.
C. Incorrect, because comparative form is always accompanied with THAN
D. Incorrect, construction is not correct
E. Incorrect, More and Higher used together which is redundant

Option A is correct

The logic of the question is that "that figure > 40 percent or that figure =40 percent "
A gives us the precise mathematical relationship that we are looking for.
That figure >= 40 percent.
To say this mathematical relationship we need at least as high as 40 percent. That figure can be higher but at least it should be 40 percent.

B is bad diction. C , D and E are not good either.

In A, isn't 'as high as' redundant? 'at least 40 percent' seems to do the job

I see your logic, but can not agree with you 100%
How will you say correct the sentence in this case?

Twenty years ago, only 100 students at Dunmore College who intended to major in chemistry were women; today that figure is higher by 40 percent at the least

KAPLAN OFFICIAL EXPLANATION

Step 1: Read the Original Sentence Carefully, Looking for Errors
Comparisons are being tested in this sentence (your hint is the use of the words “at least as high”
and the words “higher” and “more” throughout the answer choices). Here you are looking for the
construction that makes the comparison as clear and correct as possible. This sentence compares
the previous figure, or “6 percent,” with today’s figure, so you want something that is as similar in
structure as possible to “6 percent.”

Step 2: Scan and Group the Answer Choices
The comparison sounds good as is, but scan the choices for the ways in which the choices use other
comparative words like “higher” (as in (B), (C), and (E)) and “more” (as in (D) and (E)).

Step 3: Eliminate Choices Until Only One Remains
(B) is awkward and redundant; it doesn’t make sense to have both “higher than” and “at least” next
to each other. (C) changes the meaning of the sentence by saying “higher by 40 percent,” which
means something different from “higher than 40 percent.” (D) introduces the awkward and confusing
“40 percent high,” which is hard to decipher. Finally, (E) uses the egregious construction “more
higher.” The best choice is (A), “at least as high as 40 percent.”