Which of the following bones is in contact with fenestra rotundus ?

Options

A. Incus
B. Stapes
C. Malleus
D. None of these

Answer

To solve the question regarding which bone is in contact with the fenestra rotundus, let's go through the steps systematically:

### Step-by-Step Solution:

1. **Understand the Fenestra Rotundus**:
- The fenestra rotundus, also known as the round window, is a membrane-covered opening in the bony wall of the inner ear. It separates the middle ear from the inner ear.

2. **Identify the Bones of the Middle Ear**:
- The bones of the middle ear are the malleus, incus, and stapes. These are the three small bones that play a crucial role in the process of hearing.

3. **Determine the Location of the Fenestra Rotundus**:
- The fenestra rotundus is located in the inner ear, specifically at the interface between the middle ear and the cochlea of the inner ear.

4. **Analyze the Contact Points**:
- The malleus, incus, and stapes are all bones located in the middle ear. The stapes is the bone that is closest to the inner ear, but it does not make direct contact with the fenestra rotundus.

5. **Conclusion**:
- Since none of the bones (malleus, incus, or stapes) directly contact the fenestra rotundus, the answer to the question is that none of these bones are in contact with the fenestra rotundus.

### Final Answer:
- The correct option is **None of these** (Option B).