The first body segment of earthworm is

Options

A. Prostomium
B. Peristomium
C. Peristome
D. Protome

Answer

To answer the question, "The first body segment of earthworm is," we will follow these steps:

### Step-by-Step Solution:

1. **Understanding Earthworm Anatomy**:
- Earthworms belong to the phylum Annelida, which is characterized by a segmented body. Each segment is known as a metamere.

2. **Identifying the First Segment**:
- The question specifically asks for the first body segment of the earthworm. The first segment is crucial as it contains important anatomical features.

3. **Defining the Segments**:
- The first segment of the earthworm is called the **peristomium**. This segment contains the mouth of the earthworm and is essential for feeding.

4. **Differentiating Between Options**:
- **Prostomium**: This is a fleshy lobe that extends from the peristomium, but it is not considered the first body segment.
- **Peristome**: This term refers to a structure found in plants and is not related to earthworm anatomy.
- **Proton**: This term does not relate to earthworm anatomy at all.

5. **Conclusion**:
- Based on the definitions and descriptions, the correct answer is the **peristomium**, which is indeed the first body segment of the earthworm.

### Final Answer:
The first body segment of the earthworm is **peristomium**.

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