The muscular structure that helps in grinding the decaying leaves is 

Options

A. pharynx
B. oesophagus
C. gizzard
D. buccal cavity

Answer

To solve the question "The muscular structure that helps in grinding the decaying leaves is," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking for a specific muscular structure in the earthworm that is responsible for grinding decaying leaves.

2. **Identify the Options**: The options provided are:
- Pharynx
- Esophagus
- Gizzard
- Buccal cavity

3. **Review the Function of Each Option**:
- **Pharynx**: This is involved in the swallowing of food but does not grind it.
- **Esophagus**: This structure primarily conducts food from the pharynx to the gizzard and does not have a grinding function.
- **Gizzard**: This is a muscular structure that acts like teeth, grinding the food (in this case, decaying leaves) into smaller pieces.
- **Buccal Cavity**: This is the area where food is initially taken in but does not perform grinding.

4. **Determine the Correct Answer**: Since the gizzard is specifically designed to grind food, including decaying leaves, it is the correct answer.

5. **Final Answer**: The muscular structure that helps in grinding the decaying leaves is the **Gizzard**.