In earthworm, small fleshy lobe hung over mouth is known as

Options

A. Peristomium
B. Nephridiospores
C. Clitellum
D. Prostomium

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of a small fleshy lobe that hangs over the mouth of an earthworm.

2. **Identifying the Options**: The options provided are:
- A) Peristomium
- B) Nephrediospores
- C) Clitellum
- D) Prostomium

3. **Analyzing Each Option**:
- **Option A: Peristomium**: This is the first segment of the earthworm, but it is not the fleshy lobe that hangs over the mouth.
- **Option B: Nephrediospores**: These are openings of the excretory organs found on the surface of the earthworm's body, not related to the mouth area.
- **Option C: Clitellum**: This is a band of glandular tissue found on segments 14 to 16, involved in reproduction, and does not hang over the mouth.
- **Option D: Prostomium**: This is the small fleshy lobe that extends from the peristomium and hangs over the mouth. It is involved in the opening and closing of the mouth.

4. **Conclusion**: The correct answer is **D) Prostomium**, as it is the structure that fits the description given in the question.

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