Two bars B1 and B2 of different materials and the same size are subjected to the same tensile force. If the bars have unit elongation in the ratio of 3:7 respectively, then the
ratio of modulus ofelasticity of the two bars B1 and B2 will be:

A

3 : 7

B

7 : 3

C

3 : 4

D

4 : 3