Assertion :Spontaneous process is an irreversible process and may be reversed by some external agency.

Reason: Decrease in enthalpy is a contributory factor for spontaneity.

A. both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. Assertion is True but the Reason is False.
D. both Assertion & Reason are false.