user
what can be smart and dumb too,it is also very near you,it is weird and cool too,it can be feared and it needs no fuel, what am i?
A: simple
B: brain
C: captain
D: thing
E: mental illness
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

B

<|end_of_solution|>