Definition: 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.
Input: Prompt: John is my father and Kate is my mother. Kate is now married to my step-father Bob. Bob is Kate's 
Completion A: ex-husband 
Completion B: friend 
Completion C: husband 
Completion D: father
Output:
Completion C