Assertion:The cranium encloses the brain during life
Reason:The eight cranium bones fit together by wavy immovable joints.

Options

A. if both assertion and reason are true and the reason is correct explanton of Assertion
B. IF both assertion and reason and reason are true but reason is not a correct explanation of assertion
C. IF assertion is true and reason is wrong
D. if both assertion and reason are wrong

Answer

To analyze the given assertion and reason, we can break down the information step by step:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "The cranium encloses the brain during life."
- This is true because the cranium, which is part of the skull, serves as a protective case for the brain throughout an individual's life.

**Hint**: Think about the function of the skull and its role in protecting the brain.

2. **Understanding the Reason**:
- The reason given is "The eight cranium bones fit together by wavy immovable joints."
- This statement is also true. The cranium is made up of eight bones: frontal, parietal (2), temporal (2), occipital, sphenoid, and ethmoid. These bones are connected by sutures, which are types of fibrous joints that do not allow movement.

**Hint**: Recall the names of the cranial bones and their connections.

3. **Evaluating the Relationship**:
- The reason explains how the cranium is structured and why it can effectively enclose the brain. The immovable joints ensure that the bones remain fixed in place, providing a stable protective casing for the brain.

**Hint**: Consider how the structure of the cranium relates to its function.

4. **Conclusion**:
- Since both the assertion and reason are true, and the reason correctly explains the assertion, the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

**Hint**: Look for options that indicate both statements are true and that one explains the other.

### Final Answer:
The correct answer is **Option 1**: Both assertion and reason are true, and reason is the correct explanation of assertion.