user
How can you physically stand behind your friend as he physically stands behind you?
A: chest to chest
B: scale
C: athlete
D: by standing back to back
E: companionship
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

D

<|end_of_solution|>