Assertion: The cell potential of mercury cell is 1.35 V which remains constant.
Reason: In mercury cell, the electrolyte is a paste of KOH and HgO.
A. If both assertion and reason are true, and reason is the true explanation of the assertion
B. if both assertion and reason are true, but reason is not the true explanation of the assertion.
C. if assertion is true, but reason is false.
D. If both assertion and reason are false.