The structure(s) that open into the pharynx 

Options

A. Trachea
B. Oesophagus
C. Epiglottis
D. Both A and B

Explanation

To answer the question regarding the structures that open into the pharynx, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Pharynx**: The pharynx is a muscular tube that serves as a common passage for both food and air. It connects the nasal cavity and mouth to the esophagus and trachea.

2. **Identifying Structures**: The two main structures that open into the pharynx are:
- **Trachea (Windpipe)**: This is the airway that leads to the lungs. Air passes from the pharynx into the trachea.
- **Esophagus (Food Pipe)**: This is the tube that carries food from the pharynx to the stomach.

3. **Role of the Epiglottis**: The epiglottis is a flap of cartilage that covers the glottis (the opening to the trachea) during swallowing to prevent food from entering the trachea. However, it does not open into the pharynx itself; rather, it functions to direct food into the esophagus and air into the trachea.

4. **Conclusion**: Therefore, the correct answer to the question is that both the trachea and esophagus open into the pharynx.

### Final Answer:
The structures that open into the pharynx are the **trachea** and **esophagus**.

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