A block of mass 2.0 $$\mathrm{kg}$$ is suspended from the ceiling by a massless string. The string is taut when the block is stationary. Suddenly, the string breaks and the block starts falling freely. The difference in the tension in the string just before and after it breaks is

A

9.8 N

B

19.6 N

C

4.9 N

D

zero