Reading the initial sentence, we should notice the phrase "more fuel-efficient ... than". This tells us that we're dealing with a comparison: the fuel efficiency of small cars in the past vs. the fuel efficiency of small cars in the present.
However, we might notice something sounds odd about the comparison in first sentence. Small cars are "more fuel efficient
now than
at any time in their production history". Well ... doesn't "any time in their production history" include "now"? Meaning that small cars are more fuel efficient
now than they are ...
also now?
The impossible comparison is a classic GMAT trap, though this one doesn't show up all that often. When we compare one thing in a group to the rest of the things in the group, we need to make sure that we exclude the one thing from the group we compare it to, typically using the word "other". For example:
- Keisha scored higher on the the test than all of the students in her class.
is illogical. Keisha is one of the students in her class; this sentence tells us she scored higher than all of them - including herself. We can correct this by excluding Keisha from the class in our comparison:
- Keisha scored higher on the the test than all of the other students in her class.
Looking back at our sentence, we can eliminate any answers that use the phrase "at any time": A, B, and E.
Let's look at the comparisons made in C and D.
C tells us that manufacturers make "small cars that are more fuel efficient than those [small cars] at any other time in production history". So the small cars manufacturers make now are more efficient than the small cars they made before.
D tells us that manufacturers make "more fuel efficient small cars than those [manufacturers] at any other time in their production history". This has a slightly different meaning. Now, the sentence tells us that the manufacturers make more fuel-efficient small cars,
not that the small cars they make are more fuel-efficient. So with C, the manufacturers are increasing fuel efficiency, while in D, the manufacturers are increasing the number of cars.
When dealing with issues of meaning on Sentence Correction questions,
we want the correct answer to capture the meaning intended by the original sentence. Ignoring the errors in the original sentence, we see that it conveys the idea of "more fuel-efficiency" not "more cars", making D wrong and C correct.
We actually featured this problem recently on the
PrepScholar GMAT blog as one of the
5 Hardest Sentence Correction Questions. I recommend checking out the article for more strategies and trends we can take away from this and other 700+ level problems!
