To determine which option has the edible part belonging to the seed in a fleshy fruit, we will analyze each option step by step.
### Step-by-Step Solution:
1. **Understanding Fleshy Fruits**:
- Fleshy fruits are characterized by their three layers: epicarp (outer layer), mesocarp (middle layer), and endocarp (inner layer). These layers are typically soft and edible.
2. **Analyzing Each Option**:
- **I. Nut**:
- Nuts are classified as dry fruits. They do not have differentiated layers of pericarp (epicarp, mesocarp, endocarp) and do not have an edible fleshy part. Therefore, nuts are not considered fleshy fruits.
- **II. Legume**:
- Legumes, such as peas and beans, are also dry fruits. They do not have a fleshy part and their seeds are not surrounded by a fleshy pericarp. Thus, legumes are not fleshy fruits either.
- **III. Drupe of Coconut**:
- The coconut is classified as a drupe, which is a type of fleshy fruit. In a coconut, the endocarp is the hard shell, while the mesocarp is the fibrous husk, and the epicarp is the outer layer. The edible part of the coconut is the white flesh found inside, which is derived from the endocarp. Therefore, this option is a fleshy fruit with an edible part.
- **IV. Caryopsis**:
- Caryopsis, such as in grains like wheat and rice, is also a dry fruit. It has a single seed that is fused with the fruit wall, and it does not have the typical fleshy layers. Thus, it does not qualify as a fleshy fruit.
3. **Conclusion**:
- Among the given options, only the drupe of coconut has an edible part that belongs to the seed in a fleshy fruit. Therefore, the correct answer is **III. Drupe of Coconut**.
### Final Answer:
The edible part belongs to the seed in this fleshy fruit: **III. Drupe of Coconut**.
