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".
Input: . a man in a red shirt at an outdoor tennis court <sep> (A) of some sort throws a ball at a yellow ball, the yellow ball rolls into the net and the man and woman run to retrieve the ball. (B) says something to the camera and does some hand motions at the black object on the court. (C) is giving a tutorial on to return a serve and how to hold the racket. (D) does volley tennis and serves the ball.
Output:
C