Atree is standing in the middle of a meadow. as you watch, the wind begins
to blow and the tree bends. which statement best explains how you could
tell
that a net force was acting on the tree?
oa) the tree had momentum.
ob) the tree was stationary and began to move.
oc) the tree was already in motion and sped up.
od) the tree was already in motion and changed direction.

B) The tree was stationary and began to move.

Explanation:

This situation can be explained by using Newton's first law of motion, which states that

"An object at rest (or in motion at constant velocity) stays at rest (or in motion at constant velocity) unless a net non-zero force is exerted on it"

This means that an object at rest can start moving if and only if there is a net non-zero force acting on it.

In the example in the problem, the tree is initially stationary. Later, it started to move. According to Newton's first law, therefore, there must be a net force that caused this change of state of motion of the tree. Therefore, the correct answer is

B) The tree was stationary and began to move.

whichever one it is, it's definitely not one that you included on the list you provided.

it is called kinetic energy