Answer: The acceleration of an object will decrease
Explanation: This happens as if the mass of an object increases then the acceleration of the body decreases as acceleartion is directly proportional to the mass of the body by Newton's 2nd law F=MA we can say the more mass an object has the more net force needs to be applied to make it start accelerating
I believe the answers you're looking for is effectively but not efficiently. The reason its these choices is because although you finished the job, it was not done in the best way possible. So it was effective, but not efficient.
