Sunken stomata are usually found in

Options

A. `C_3` plants
B. CAM plants
C. Insectivorous
D. Phanerogams

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the type of plants that usually have sunken stomata. Stomata are small openings on the surface of leaves that allow for gas exchange.

2. **Analyzing the Options**: The options provided include:
- C3 plants
- CAM plants
- Insectivorous plants
- Pteridophytes (Fenerogams)

3. **Evaluating C3 Plants**: C3 plants typically have stomata that are not sunken. They are adapted to environments where water loss is not as critical. Therefore, this option is incorrect.

4. **Evaluating CAM Plants**: CAM (Crassulacean Acid Metabolism) plants are adapted to arid environments. They have sunken stomata to minimize water loss through transpiration, making this option correct.

5. **Evaluating Insectivorous Plants**: Insectivorous plants, such as Venus flytraps, do not have stomata in the traditional sense, as they primarily rely on capturing insects for nutrients. Thus, this option is also incorrect.

6. **Evaluating Pteridophytes (Fenerogams)**: Pteridophytes, which include ferns, typically have prominent stomata and are not known for having sunken stomata. Therefore, this option is incorrect.

7. **Conclusion**: The correct answer is CAM plants, as they possess sunken stomata to reduce water loss through transpiration.

### Final Answer:
Sunken stomata are usually found in **CAM plants**.