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: Professor Downey has solved the most difficult NLP problem. He is 
Completion A: sad that it was a difficult problem. 
Completion B: sad that he has solved the difficult problem. 
Completion C: very sad. 
Completion D: happy to have solved it.
Completion D

Prompt: A cat is running full speed across a carpet.  It 
Completion A: leaps over a handbag on the floor and keeps going. 
Completion B: proves theorems daily. 
Completion C: asks a question of each person in the room. 
Completion D: turns its head to lap up the milk.
Completion A

Prompt: A child is happy at his dog for jumping over a fence. He 
Completion A: punishes his dog for the accomplishment 
Completion B: pets his fence and paints his dog 
Completion C: builds another one 
Completion D: rewards it with something it likes

Completion D