user
I have four legs in the morning  I have two legs in the mid-day  I have and three legs in the evening  What am I?
A: single
B: period
C: human being
D: gown
E: kneecap
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

C

<|end_of_solution|>