In earthworm, `14^(th)` to `16^(th)` segments are covered by a prominent dark band of glandular tissue called

Options

A. a) Typhlosole
B. b) Gizzard
C. c) Prostomium
D. d) Clitellum

Explanation

To answer the question regarding the prominent dark band of glandular tissue covering the 14th to 16th segments in earthworms, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Segments**: The question specifies segments 14 to 16 of the earthworm. It is important to focus on these specific segments to find the correct glandular tissue.

2. **Understand the Options**: The options provided are:
- A. Tiflosol
- B. Gizzard
- C. Prostomium
- D. Clitellum

3. **Recall the Function of Each Option**:
- **Tiflosol**: A fold in the intestine that increases surface area for absorption.
- **Gizzard**: A muscular part of the digestive system that grinds food.
- **Prostomium**: The anterior part of the earthworm, which is not related to the segments mentioned.
- **Clitellum**: A thickened, glandular section of the body wall in certain annelids, including earthworms, that is involved in reproduction.

4. **Determine the Correct Answer**: The clitellum is specifically found in segments 14 to 16 of the earthworm and is responsible for secreting mucus and albumin, which are essential for the formation of a cocoon for fertilization.

5. **Conclude the Answer**: Based on the above information, the correct answer to the question is **D. Clitellum**.