In Earthworm arrangment of blood vessels is

Options

A. Different in last 15 segments
B. Different in first 13 segments
C. Same throughout
D. Different in middle 13 segments

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the arrangement of blood vessels in earthworms. We need to identify how the blood vessels are organized in different segments of the earthworm's body.

2. **Types of Blood Vessels**: The blood vessels in earthworms are categorized into three types:
- Longitudinal blood vessels
- Lateral blood vessels
- Intestinal plexus

3. **Segmental Arrangement**: The earthworm's body is divided into segments. The arrangement of blood vessels varies between these segments:
- The first 13 segments have a different arrangement of blood vessels compared to the segments that follow.
- The segments behind the first 13 have a different configuration of blood vessels.

4. **Conclusion**: Based on the information, we can conclude that the arrangement of blood vessels in earthworms is different in the first 13 segments compared to the segments behind them.

5. **Final Answer**: Therefore, the correct answer to the question is that the arrangement of blood vessels is different in the first 13 segments.