WILL GIVE MEDAL!

Work is being done in which of these situations? All motions are at a constant velocity (including velocity = zero).

A) Jessica pushes a 25 kilogram cart a distance of 10 meters.
B) Bane carries a 20 kilogram box a distance of 50 meters.
C) A weightlifter holds a 100 kilogram barbell over his head.
D) Ali is trying to push a truck away from the parking lot.
Yana carries a 5 kilogram bag a distance of 1 kilometer.

Question

WILL GIVE MEDAL! 

Work is being done in which of these situations? All motions are at a constant velocity (including velocity = zero).

A) Jessica pushes a 25 kilogram cart a distance of 10 meters.
B) Bane carries a 20 kilogram box a distance of 50 meters.
C) A weightlifter holds a 100 kilogram barbell over his head.
D) Ali is trying to push a truck away from the parking lot.
Yana carries a 5 kilogram bag a distance of 1 kilometer.