Riddle

I hide in a dark tunnel awaiting my time. I can only be released by pulling back. Once released, I may do unstoppable damage. What am I?

Choose an answer

A.An arrow
B.A firework
C.A cannonball
D.Bullet
Hint: It's a word with 6 letters, starting with "B".

Answer

Bullet

Why this is the answer

A bullet waits inside a gun's dark barrel until the trigger ('pulling back' the hammer) releases it to strike with force.

This riddle is filed under "What Am I?" Riddles and rated Medium.