Which of the following option is incorrect about the larynx (sound box) ?

Options

A. (a) It is a bony box
B. (b) Glottis is the opening into the larynx.
C. (c) During swallowing of food glottis is covered by epiglottis to prevent food entry into the larynx.
D. (d) All of these

Explanation

To determine which statement is incorrect about the larynx (sound box), we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding the Structure of the Larynx**:
- The larynx is located in the neck region, below the pharynx. It is commonly referred to as the voice box or sound box because it contains the vocal cords.

2. **Identifying the Composition of the Larynx**:
- The larynx is made up of cartilage, not bone. This is a crucial point because it helps differentiate it from other structures in the body.

3. **Examining the Function of the Vocal Cords**:
- The vocal cords, which are flaps of cartilage located within the larynx, are responsible for producing sound. They vibrate when air passes through them, creating sound.

4. **Understanding the Role of the Glottis and Epiglottis**:
- The glottis is the opening of the larynx, and the epiglottis is a flap-like structure that covers the glottis during swallowing to prevent food from entering the larynx.

5. **Analyzing Each Statement**:
- **Statement A**: "It is a bony box." - This is incorrect because the larynx is made of cartilage.
- **Statement B**: "Glottis is the opening into the larynx." - This is correct.
- **Statement C**: "During swallowing of food, glottis is covered by epiglottis to prevent the entry of food into the larynx." - This is also correct.
- **Statement D**: "All of these." - This is incorrect because Statement A is false.

6. **Conclusion**:
- The incorrect statement regarding the larynx is **Statement A**: "It is a bony box." Therefore, the correct answer is **Option A**.

### Final Answer:
The correct answer is **Option A**: It is a bony box.