Correct use of Discriminate ..... X ..... Y

[AG]

After a few weeks’ experience, apprentice jewelers can usually begin to discriminate, though not with absolute certainty, genuine diamonds from imitation diamonds.
(A) genuine diamonds from imitation diamonds
(B) genuine diamonds apart from imitations
(C) between genuine diamonds and imitation diamonds
(D) among genuine diamonds and imitation diamonds
(E) whether diamonds are imitation or genuine

[nag]

Correct idiom is "between X and Y"
C

[AG]

but I found evidence that discriminate X from Y is correct english.

See the following sources:

http://www.thefreedictionary.com/discriminate
1. To perceive the distinguishing features of; recognize as distinct: discriminate right from wrong.
2. To make or constitute a distinction in or between: methods that discriminate science from pseudoscience.

http://dictionary.reference.com/browse/discriminate
3. to make or constitute a distinction in or between; differentiate: a mark that discriminates the original from the copy.

[RonPurewal]

please post a source for this question, or will have to delete the thread. if you don't know the source and/or the source happens to be one of our banned sources, then just edit your original post so that it merely asks a question about the idiom (or ask us to edit it, if you don't have the capability).

--

here's the usual usage of those two:
'discriminate between' is something done by an observer. for instance,
i can discriminate between alto and soprano voices when i listen to classical singers.

'discriminate from' is something innate to the items being distinguished from one another. for instance,
differences in pitch are what discriminates alto voices from soprano voices.

but the gmat is a strange animal, and its usages might differ from these conventions.