If 96500 coulombs of electricity liberates one gram equivalent of any substance, the time taken for a current of `0.15` amperes to deposite 20 mg of copper from a solution of copper sulphate is (Chemical equivalent of copper = 32)
A. 5 min 20 sec
B. 6 min 42 sec
C. 4 min 40 sec
D. 5 min 50 sec
