In an unconfined compression test , a sample clay 100 mm long and 50 mm in diameter fails under a load of 150 N at 10% strain . what is the shearing resistance taking in to account the effect of change in cross section of the sample ?

A

0.068 $$\frac{N}{mm^{2}}$$

B

0.088 $$\frac{N}{mm^{2}}$$

C

0.034 $$\frac{N}{mm^{2}}$$

D

0.044 $$\frac{N}{mm^{2}}$$