Answer:
c. continually spin
Step-by-step explanation:
If the torque on both sides of the balance is same both n magnitude and in direction, then the balance will start to spin continually. Because, the same torque at each end can only ne caused by a couple force. When two unlike, parallel and equal forces act on a body at different lines of action, they are called as Couple. This couple force causes object to rotate in the direction of the forces. Hence, the balance, under the influence of these torques will start to spin continually.
So, the correct option will be:
c. continually spin