Eustachian tube is supported by : -

Options

A. Elastin cartilage
B. white fibros cartilage
C. Calcified cartilage
D. Hyaline catilage

Answer

### Step-by-Step Solution:

1. **Identify the Structure**: The Eustachian tube is a narrow passage that connects the pharynx to the middle ear. Understanding its anatomical location is crucial for determining its support structure.

2. **Understand the Types of Cartilage**: There are several types of cartilage in the body, including:
- **Elastin Cartilage**: Also known as elastic cartilage, it contains a high proportion of elastic fibers, allowing it to maintain shape while being flexible.
- **White Fibrous Cartilage**: Rich in collagen fibers, providing strength and support, typically found in joints.
- **Calcified Cartilage**: A transitional type of cartilage that connects hyaline cartilage to bone.
- **Hyaline Cartilage**: The most common type, found in areas like the ribs, nose, and trachea.

3. **Determine the Supporting Cartilage for the Eustachian Tube**: The Eustachian tube requires a type of cartilage that allows flexibility and elasticity due to its function in equalizing air pressure in the middle ear.

4. **Conclusion**: The Eustachian tube is primarily supported by **elastin cartilage** (also known as elastic cartilage). This type of cartilage is suitable for structures that require both support and flexibility.

5. **Final Answer**: The correct option is **elastin cartilage**.