External ears are supported by:

Options

A. Bone
B. Tendon
C. Ligaments
D. Cartilage

Explanation

To solve the question "External ears are supported by:", we will analyze the options given and determine which one correctly describes the structure that supports the external ear.

### Step-by-Step Solution:

1. **Understand the Structure of the Ear**:
- The human ear is divided into three parts: the external ear, the middle ear, and the inner ear. The external ear is also known as the pinna or auricle.

2. **Identify the Function of the External Ear**:
- The external ear is a fleshy flap that helps to funnel sound waves into the external auditory canal.

3. **Evaluate the Options Provided**:
- **Option A: Bone** - This is incorrect because the external ear is not primarily supported by bone. The ear structure does not have a direct bony support.
- **Option B: Tendon** - This is also incorrect. Tendons connect muscles to bones, and they do not play a role in supporting the external ear.
- **Option C: Ligament** - This option is incorrect as well. Ligaments connect bones to other bones, and they do not support the external ear structure.
- **Option D: Cartilage** - This is the correct option. The external ear (pinna or auricle) is supported by cartilage, which provides the necessary flexibility and structure.

4. **Conclusion**:
- After evaluating all the options, we conclude that the external ears are supported by **cartilage**. Therefore, the correct answer is **Option D: Cartilage**.