An object moving forward at 10 m/s suddenly begins moving backward at 5 m/s. what is the most accurate explanation for this change?

the object was traveling in a straight line until it hit a brick wall and bounced backward.

the force pushing back on the object became greater than the force pushing the object forward.

the forces acting on the object were equal at first. then the forces became unequal, causing the object to change its direction.

the forces were balanced in the forward direction. then they became balanced in the backward direction.