When does current flow in a PN junction?

Q. When does current flow in a PN junction?

A.            When both p-type and n-type elements are at same potential

B.            When there is no potential at either p-type or n-type elements

C.            When p-type element is at more positive potential than n-type

D.            When n-type element is at more positive potential than n-type

Answer: When p-type element is at more positive potential than n-type