One of the following is common in earthworm and cockroach

Options

A. Double solid and ventral nerve cord
B. Presence of nephridia
C. Equal body segments
D. Malpighian tubules

Answer

To solve the question "One of the following is common in earthworm and cockroach," we need to analyze the options provided and identify the common feature between the two organisms.

### Step-by-Step Solution:

1. **Understand the Organisms**:
- Earthworm is an annelid (a segmented worm).
- Cockroach is an arthropod (an insect).

2. **Review the Options**:
- **Option 1**: Double solid and ventral nerve cord.
- **Option 2**: Presence of nephridia.
- **Option 3**: Equal body segments.
- **Option 4**: Malpighian tubules.

3. **Analyze Each Option**:
- **Option 1**: Double solid and ventral nerve cord.
- Both earthworms and cockroaches have a ventral nerve cord, which is a characteristic of many invertebrates. This option is likely correct.
- **Option 2**: Presence of nephridia.
- Nephridia are excretory organs found in earthworms but not in cockroaches. This option is incorrect.
- **Option 3**: Equal body segments.
- Earthworms have a segmented body, but cockroaches do not have equal body segments. This option is incorrect.
- **Option 4**: Malpighian tubules.
- Malpighian tubules are excretory organs found in cockroaches, not in earthworms. This option is incorrect.

4. **Conclusion**:
- The only feature that is common in both earthworms and cockroaches is the **double solid and ventral nerve cord**. Therefore, the correct answer is **Option 1**.

### Final Answer:
The common feature in earthworm and cockroach is the **double solid and ventral nerve cord**.

---