Assertion (A): Enthalpy of graphite is lower than that of diamond.
Reason (R ) : Entropy of graphite is lower than that of diamond.

Options

A. If both (A) and (R ) are correct, and (R ) is the correct explanation for (A).
B. If the both (A) and (R ) are correct, but(R ) is not a correct explanation for (A).
C. If (A) is correct, but (R ) is incorrect.
D. If (A) is incorrect, but (R ) is correct.

Explanation

To solve the assertion and reason question, we need to analyze both statements carefully.

### Step 1: Analyze the Assertion
**Assertion (A): Enthalpy of graphite is lower than that of diamond.**

- Graphite is known to be the most stable allotrope of carbon, while diamond is less stable due to its three-dimensional structure.
- Stability is inversely related to enthalpy; a more stable substance has lower enthalpy.
- Therefore, the assertion is **true**: the enthalpy of graphite is indeed lower than that of diamond.
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