Paul wrote:
Unlike a hurricane, which can be observed from within, a tornado is so small that such a study has not been practical.
(A) that such a study has not been practical
(B) that studying it that way has not been impractical
(C) for such studies as this to have been impractical
(D) as to not make such a study practical
(E) as to be impractical of study
There is a lot we can do with meaning on this question. The question is setting up a comparison between how hurricanes and tornadoes can be studied. Hurricanes can be studied from within but tornadoes cannot. Let's go over each answer choice.
A - "such a study" refers us back to how hurricanes are studied from within and how this type of internal study is not practical with tornadoes - CORRECT
B - "has not been impractical" brings in a double negative, changing the meaning to say that we CAN study tornadoes from within - INCORRECT
C - "so small for" is not idiomatic, "such studies as this" does not necessarily refer back to the internal studies done in hurricanes, "to have been impractical" is awkward phrasing - INCORRECT
D - "not make such a study practical" is unclear wording and not preferred ("not make practical" is weak/unclear wording, "impractical" is strong/clear wording) - INCORRECT
E - uses the stronger "impractical" wording, however the meaning changes in this answer; the original intent was that tornadoes could not be studied FROM WITHIN, but this wording suggests that tornadoes cannot be studied AT ALL - INCORRECT
KW