Sentence Correction

In order to determine whether or not white cabbage butterflies discriminate among flowers that contain nectar and those that do not, entomologists have designed experiment that they hope will reveal the flower - visiting pattern of these butterflies.

A.In order to determine whether or not white cabbage butterflies discriminate among
B.To determine whether white cabbage butterflies discriminate between
C.For determining if white cabbage butterflies discriminate or not between
D.Because of wanting to determine whether white cabbage butterflies discriminate between
E.Since they wanted to determine if white cabbage butterflies discriminate among

OA:B

Source-GMATPrep EP-1

GMATGuruNY wrote:
A: whether or not
The red portion is redundant, since it can be omitted with no loss of meaning.
The following is sufficient to convey the intended meaning:
To determine whether white cabbage butterflies discriminate, entomologists have designed an experiment.
Eliminate A.

if serves to introduce a CONDITION.
whether serves to introduce ALTERNATIVES.
The intent here is to discuss alternatives: white cabbage butterflies either DISCRIMINATE or DO NOT DISCRIMINATE.
Thus, the usage of if in C and E is inappropriate.
Eliminate C and E.

D: Because of wanting to determine whether white cabbage butterflies disciminate, entomologists have designed an experiment.
The red portion is redundant, since it can be omitted with no loss of meaning.
The following is sufficient to convey the intended meaning:
To determine whether white cabbage butterflies discriminate, entomologists have designed an experiment.
Eliminate D.

The correct answer is B.

Hi Mitch,
Can we also mark A and E wrong because of the use of 'among' at the end of underlined portion. Generally among is used for more than two entities and between for just two, and here we have just two types of flowers. Is this reasoning okay?

Thanks!
Manik

manik11 wrote:Hi Mitch,
Can we also mark A and E wrong because of the use of 'among' at the end of underlined portion. Generally among is used for more than two entities and between for just two, and here we have just two types of flowers. Is this reasoning okay?

Thanks!
Manik

Correct!
For two entities, we use not among but between.
Eliminate A and E.