user
this riddle is about a library has alot of books!
A: national library
B: squash bug
C: blindness
D: scar
E: couples
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

A

<|end_of_solution|>