In earthworms, the respiration takes place through

Options

A. Moist skin
B. Gills
C. Lungs
D. Tracheal System

Answer

### Step-by-Step Solution:

1. **Identify the Organism**: The question refers to earthworms, which belong to the group of invertebrates and specifically to the phylum Annelida.

2. **Understand the Respiratory System**: Earthworms do not possess specialized respiratory organs such as lungs or gills. Instead, they rely on their skin for respiration.

3. **Mechanism of Respiration**: The process of respiration in earthworms occurs through simple diffusion. This means that gases (oxygen and carbon dioxide) move across the skin's surface without the need for specialized structures.

4. **Gaseous Exchange**: Earthworms take in oxygen from the environment through their moist skin and expel carbon dioxide back into the environment. This process is efficient due to the large surface area of their skin and the moisture that facilitates gas exchange.

5. **Conclusion**: Therefore, the correct answer to the question is that respiration in earthworms takes place through their moist skin.