Differentiate between ‘before’ and ‘after’ in the context of prepositions of time.

A. The main difference between ‘before’ and ‘after’ is the number of letters in each word.

B. The difference between ‘before’ and ‘after’ is the color of the words used.

C. The main difference between ‘before’ and ‘after’ in the context of prepositions of time is the direction of the time reference.

D. In the context of prepositions of time, ‘before’ refers to the future and ‘after’ refers to the past.