What does an unbalanced force cause an object to do?

An unbalanced force causes an object to change its motion, which can include altering its speed, direction, or both. Newton's First Law of Motion states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. When forces acting on an object are not equal in magnitude and direction, the resulting net force leads to an acceleration of that object. This change in motion is a fundamental concept in physics, illustrating how unbalanced forces affect the dynamics of an object in various scenarios, such as accelerating a car or making a ball roll down a hill.

The other options suggest that the object would either remain in its current state of motion or speed, which contradicts the principles behind forces and motion. When forces are balanced, there is no change in motion; thus, the object would stay at rest or keep moving uniformly.