In which one of the following situations is linear momentum not conserved?
A) A bomb suspended by a string explodes into one hundred fragments.
B) A bowling ball collides with ten pins.
C) A golf ball is struck by a club.
D) An astronaut floating in space throws a hammer away and subsequently moves in the opposite direction.
E) A tree limb is struck by lightning and falls to the ground.
The Attempt at a Solution
I have no idea... I thought momentum was always conserved? Can someone help explain this please? Thanks!!!