Given a prompt and four completions, select the completion that is the most plausible in continuing or answering the prompt. This task is designed to test common sense and has various categories ranging between idioms, negated statements, polysemy, subject referencing, and quantitative reasoning. Generate either Completion A, Completion B, Completion C, or Completion D.

Prompt: He is taking a math exam in the classroom, he 
Completion A: plays the video game. 
Completion B: chats with his mother. 
Completion C: returns home. 
Completion D: tries his best to finish it.
Completion D