Assertion: `NAND` or `NOR` gates are called digital building blocks.
Reason: The repeated use of `NAND` (or `NOR`) gates can produce all the basic or complicated gates.
A. if both the Assertion and Reason are true and the Reason is the correct explanation of Assertion.
B. if both the Assertion and Reason are true but the reason in not a correct explanation of the Assertion.
C. if the Assertion is true but the Reason is false.
D. if both Assertion and Reason are false.
