The structures in a human that provide balance are located in the :

Options

A. pinna
B. middle ear
C. inner ear
D. eustachian tubes

Explanation

To answer the question about where the structures in a human that provide balance are located, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Options**: The question provides four options: pinna, middle ear, inner ear, and Eustachian tube.

2. **Understand the Function of Each Part**:
- **Pinna**: This is the outer part of the ear that collects sound waves but does not play a role in balance.
- **Middle Ear**: This part contains the eardrum and ossicles (small bones) that transmit sound but is not involved in maintaining balance.
- **Inner Ear**: This part contains structures that are crucial for balance and hearing. It includes the cochlea (for hearing) and the vestibular system (for balance).
- **Eustachian Tube**: This tube connects the middle ear to the throat and helps equalize pressure but does not contribute to balance.

3. **Focus on the Inner Ear**: The inner ear houses the vestibular system, which is responsible for maintaining balance. It consists of:
- **Semicircular Canals**: Three fluid-filled canals arranged at right angles to each other, detecting rotational movements.
- **Otolith Organs**: These include the utricle and saccule, which detect linear acceleration and the effects of gravity.

4. **Conclude the Answer**: Based on the functions of these structures, the correct answer to the question is that the structures that provide balance are located in the **inner ear**.

### Final Answer:
The structures in a human that provide balance are located in the **inner ear**.

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