An object at rest will remain at rest and an object in straight-line motion will remain in straight-line motion unless acted upon by a(n)
a. force
b. balanced force
c. unbalanced force
d. greater force

C. Unbalanced force

Explanation:

From first law of motion, an object retains it state of rest or motion unless an unbalanced force acts upon it. Thus, correct option is C.

Option A is incorrect because a force is either a pull or push action on a body.

Option B is incorrect because a balanced force means that net force on the body is zero which would not cause any change in motion.

Option D is incorrect because it does not provide information about force being greater to which force.

i guess it’s a and b