Statement-1 :Graphite can be converted into diamond by application of very high pressure and temperature. Using a suitable catalyst.
Statement-2: Graphite is thermodynamically more stable and less dense than diamond.

Options

A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1
B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1
C. Statement-1 is True, Statement-2 is False.
D. Statement-1 is False, Statement-2 is True.

Explanation

To analyze the statements provided in the question, we will break down each statement and evaluate their correctness step by step.

### Step 1: Evaluate Statement 1
**Statement 1**: Graphite can be converted into diamond by application of very high pressure and temperature using a suitable catalyst.

- **Explanation**: Graphite can indeed be converted into diamond under specific conditions. This transformation requires extremely high pressure and temperature. The presence of a catalyst can facilitate this conversion, making it more efficient. Therefore, this statement is **True**.

### Step 2: Evaluate Statement 2
**Statement 2**: Graphite is thermodynamically more stable and less dense than diamond.

- **Explanation**: Graphite is known to be thermodynamically more stable than diamond at standard conditions. This is due to the arrangement of carbon atoms in graphite, which allows for delocalized electrons and strong bonding, leading to greater stability. Additionally, graphite has a layered structure with significant space between the layers, making it less dense than diamond, which has a more compact structure. Therefore, this statement is also **True**.

### Step 3: Analyze the Relationship Between the Statements
- The first statement discusses the conversion of graphite to diamond, while the second statement explains the stability and density of graphite compared to diamond. Since graphite's high stability is a reason why it can be converted into diamond under extreme conditions, the second statement serves as a correct explanation for the first statement.

### Conclusion
Both statements are true, and Statement 2 is the correct explanation for Statement 1. Therefore, the final answer is:

**Both statements are true, and Statement 2 is the correct explanation for Statement 1.**