You will be given a definition of a task first, then some input of the task.
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".

A man serves a tennis ball when playing tennis with a person in a tennis court. then <sep> (A) , the man serves again to a person behind the net, while a player stands next to him. (B) , the man serves the ball continuing the volley. (C) , the man serves the ball with a racquet leg. (D) , the man serves the ball alone and then hits it against the wall.
Output:
A