Detailed Instructions: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D". 
Q: A group of people are running around inside a gym. they <sep> (A) are engaged in a competition of kickboxing. (B) are dancing together and doing martial arts. (C) take turns throwing a disc onto the field. (D) are doing various cheerleading routines.
A:
D