Which statement best describes a chemical reaction in which energy is released?

Option (a) is the correct answer.

Explanation:

Mass movement is a process in which there is movement of sediment downhill.

For example, landslides, creep, mud flow etc all represents mass movement.

In creep, there is slow movement of particles down the slope. This is due to each slope covered with loose weathered material. This results in tilting of trees, poles, gravestones etc that are present into the ground on hill sides.

Thus, we can conclude out of the given options a rocky hill cracks after water settles and freezes. Several trees on the hill tilt due to the very slow downhill movement of rock and soil. The movement occurs over a long distance describes creep mass movement.