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.
Q: Prompt: The student did well on the professor's exam. The professor 
Completion A: set an easy test. 
Completion B: studied hard for it. 
Completion C: had a car. 
Completion D: ate apple pies.
A: 
Completion A