Cerebellum of brain is concerned with

Options

A. controlling rapid muscular activites
B. learning in early stages
C. maintaining posture, orientation and equilibrium of body
D. all of these

Explanation

### Step-by-Step Solution

1. **Identify the Cerebellum**: The cerebellum is a part of the brain located at the back, and it is often referred to as the "little brain." It is a crucial component of the hindbrain.

2. **Understand Its Functions**: The primary functions of the cerebellum include:
- Receiving information from sensory systems, including the brain and spinal cord.
- Regulating motor activities.

3. **Motor Activity Regulation**: The cerebellum is responsible for controlling voluntary movements. This includes:
- Maintaining posture.
- Ensuring equilibrium (balance).
- Coordinating movements.

4. **Specific Actions**: The cerebellum helps in:
- Coordination of muscle movements.
- Control of speech.
- Overall balanced muscular activity.

5. **Developmental Role**: In addition to these functions, the cerebellum plays a role in learning during early stages of life, particularly in childhood.

6. **Conclusion**: Based on the functions described, the cerebellum is concerned with controlling muscular activities, learning in early stages, maintaining posture, orientation, and equilibrium.

7. **Final Answer**: Therefore, the correct answer is option D, which states that the cerebellum is concerned with all of these functions.