Thermodynamically the most stable form of carbon is
(a) diamond , (b) graphite
(c) fullerenes , (d) coal

Explanation

To determine the thermodynamically most stable form of carbon among the given options, we can follow these steps:

### Step 1: Understand the Allotropes of Carbon
Carbon exists in several allotropes, which are different structural forms of the same element. The most common allotropes of carbon include:
- Diamond
- Graphite
- Fullerenes
- Coal
...