The manager rejected his application , thingk him unfit for the job, even though he had all the necessarily ___.
A qualifications
B credits
C credentials
D qualities

Which is the best choice?
my choice is A, but the given answer is C.
I would have chosen A myself.

A credential is issued by another party - an accrediting agency of some sort. Perhaps the writer of the test question thought the person was able to become accredited despite a lack of qualifications, so he lacked the qualifications although he had the credentials.

This is a poor test question, in my opinion.
thx, GG! =)

The english test made by non-native speakers is always lame.