To contract means to become smaller. Contraction = to become smaller.
The sentence that shows the proper way to use a colon is: Van Gogh painted my two favorite pieces: Starry Night and Sunflowers. The punctuation mark, colon (:) is generally used when introducing a list. But a certain rule is applied when using this punctuation mark. It should not be used if it is directly followed by a verb or preposition.
Answer:
I'm pretty sure it's B, tell me if I am wrong. :))