A heavy ball is suspended as shown in the figure given above. A quick jerk on the lower string will break that string but a slow pull on the lower string will break the upper string. The first result occurs because:

• A

  the force is too small to move the ball
• B

  air friction holds the ball back
• Correct answer
  C

  of action and reaction
• D

  the ball has inertia

Hence, the correct answer is option: 'C'.