user
Foward I am heavy, but backward I am not.  What am I?
A: progressive
B: culture
C: forward I am fat
D: word ton
E: column
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

D

<|end_of_solution|>