user
If you really want my identity,  You can unlock my name with a key.    A tree swing is my favorite toy,  Yet I'm neither little girl or boy.    I am no coin with my head and tail,  Yet I may spend time in a bar-locked jail.    I cannot speak or read or fly,  But I'll ask you this: What am I?
A: part
B: novel
C: inheritance
D: monkey
E: fluke
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

D

<|end_of_solution|>