A bar 40mm in diameter and subjected to a tensile force of 40,000 kgs. Undergoes elongation resulting in decrease in diameter considering the properties of the material as $$E = 2 \times 10^5 N/mm^2$$ and Poisson’s ratio $$\upsilon$$ as 0.3, the modulus ofrigidity will be:

A

$$76923.07 N/mm^2$$

B

$$20 \times 10^4 kg/cm^2$$

C

$$56898.50 N/mm^2$$

D

$$3 \times 10^5 kg/cm^2$$