Assertion: A current flows in a conductor only when there is an electric field within the conductor. Reason: The drift velocity of electrons in presence of electric field decreases.
Options:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false and R is also false.