If a rubber cube is taken 50 m deep in a lake, its volume reduces by 0.5%. The bulk modulus of rubber is nearly.

Excess pressure at depth h = 50 m isP=hρg=50×1000×9.8=4.9×105PaVolume strain ΔVV=−0.5%=−0.5×10−2∴Bulk modulus =−PΔVV=−4.9×105−0.5×10−2≃108PaSo the correct choice is (c).