Equilibrium and activities of the muscles and joints are monitored by:

Options

A. proprioceptors
B. tactile receptors
C. olfactory receptors
D. gustatory receptors

Explanation

To solve the question "Equilibrium and activities of the muscles and joints are monitored by:", we need to analyze the options provided and determine which type of receptor is responsible for monitoring these functions.

### Step-by-Step Solution:

1. **Identify the Options**:
The options given are:
- A) Proprioceptor
- B) Tactile receptor
- C) Olfactory receptor
- D) Gustatory receptor

2. **Understand the Function of Each Receptor**:
- **Proprioceptors**: These are specialized sensory receptors located in muscles, tendons, and joints. They provide information about body position, movement, and equilibrium.
- **Tactile Receptors**: These receptors are responsible for the sense of touch and pressure. They do not monitor muscle or joint activity.
- **Olfactory Receptors**: These receptors are responsible for the sense of smell. They are not involved in monitoring muscle or joint activities.
- **Gustatory Receptors**: These receptors are responsible for the sense of taste. They do not play a role in monitoring equilibrium or muscle activity.

3. **Evaluate the Correct Option**:
Based on the functions described:
- Proprioceptors are specifically responsible for monitoring the activities of muscles and joints as well as maintaining equilibrium.
- The other receptors (tactile, olfactory, and gustatory) do not serve this function.

4. **Conclusion**:
The correct answer to the question is **A) Proprioceptor**.

### Final Answer:
Equilibrium and activities of the muscles and joints are monitored by **Proprioceptors**.