Assertion : The e.m.f. of the driver cell in the potentiometer experiment should be greater than the e.m.f. of the cell to be determined. Reason : The fall of potential across the potentiometer wire should not be less than the e.m.f. of the cell to be determined.

• A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
• C. If assertion is true but reason is false.
• D. If the assertion and reason both are false.
• E. If assertion is false but reason is true.