Answer: [M] [T] Mary said she was going to dance all night. [M] [T] She believed him when he said he loved her. [M] [T] She said nothing that would make him angry. [M] [T] He said he would write to me, but he hasn't.
Explanation:
The answer is a.. A colon is best used in advance of a new topic or point, and not in the midst of a sentence, as is the case with the other options.
What about writing the play?