Drill 15.6 - Decoding Idioms

[ShirleyZ833]

I don’t understand why the answer for the following question in Drill 15.6 - Decoding Idioms are the following. Can you please explain?

#2. He can hardly be called a liberal, for his voting record belies the beliefs the professes to hold. (correct answer according to answer key is B)
A). He is not really a liberal because he votes in a way that goes against liberalism. << this is the answer I consider correct
B). He is a very strong liberal and always supports liberal beliefs with his vote. << correct answer according to answer key
C). He is slightly liberal, and his voting record goes along with his beliefs.

[RonPurewal]

what is the source of these problems?

thank you.