问题:
[单选题]The difference between an idiom and a non-idiom lies in __________.
Awhether the meaning of the expression can be predicted from its separate units.
Bwhether the meaning of the expression can be translated into another language.
Cwhether the meaning of the expression can be understood by the people who use it.
Dwhether the meaning of the expression can be guessed by the listeners.