Stereocilia occur in

Options

A. Columnar epithelium of stomach
B. Pseudostratified columnar epithelium of epididymis
C. Pseudostratified columnar epithelium of trachea
D. Stratified columnar epithelium of pharynx.

Answer

### Step-by-Step Solution:

1. **Understanding Stereocilia**:
- Stereocilia are specialized cellular projections that are cylindrical in shape and non-motile. They are not to be confused with cilia, which are motile.

2. **Identifying the Locations of Stereocilia**:
- Stereocilia are primarily found in the male reproductive system, particularly in the epididymis and vas deferens. This is crucial for understanding where they occur.

3. **Analyzing the Options**:
- The options provided are:
- A) Columnar epithelium of stomach
- B) Pseudostratified columnar epithelium of epidermis
- C) Pseudostratified columnar epithelium of trachea
- D) Stratified columnar epithelium of pharynx
- We need to determine which of these options is correct based on the presence of stereocilia.

4. **Evaluating Each Option**:
- **Columnar epithelium of stomach**: This type of epithelium does not contain stereocilia.
- **Pseudostratified columnar epithelium of epidermis**: This option is misleading as epidermis is not typically lined with pseudostratified columnar epithelium.
- **Pseudostratified columnar epithelium of trachea**: This epithelium contains cilia but not stereocilia.
- **Stratified columnar epithelium of pharynx**: This type of epithelium also does not contain stereocilia.

5. **Conclusion**:
- The correct answer is that stereocilia occur in the **pseudostratified columnar epithelium of the epididymis and vas deferens**. However, since the options provided do not include these specific locations, the closest correct option is **B) Pseudostratified columnar epithelium of epidermis**, although it should be noted that the epidermis typically does not have this type of epithelium.