Teacher: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". 
Teacher: Now, understand the problem? Solve this instance: People are seen walking around a track and sitting down. One stands before a track and looks off into the distance. he <sep> (A) throws a ball up into a pit. (B) lifts up his arm and walks off the track. (C) yells to an audience and raises his arms up. (D) runs down the track and into a sand pit.
Student:
D