Assertion: Ulna is logner than radius.
Reason: It has large olecranon process.

Options

A. If both assertion and reason are ture and reason is the corect explanation of assertion
B. If both assertion and reason are ture but reson is not the correct explanation of assertion
C. If assertion is true reason is false
D. If both assertion and reason are false

Explanation

To solve the assertion and reason question regarding the ulna and radius, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Ulna is longer than radius."
- This is a factual statement in human anatomy. The ulna, which is located on the inner side of the forearm, is indeed longer than the radius, which is on the outer side.

2. **Understanding the Reason**:
- The reason given is "It has a large olecranon process."
- The olecranon process is a bony prominence at the proximal end of the ulna that forms the elbow's tip. This structure contributes to the ulna's length compared to the radius.

3. **Evaluating the Relationship**:
- The reason provided explains why the assertion is true. The large olecranon process of the ulna contributes to its overall length and prominence in the forearm structure.

4. **Conclusion**:
- Since both the assertion and the reason are true, and the reason correctly explains the assertion, we conclude that the answer is:
- **Both Assertion and Reason are true, and the Reason is the correct explanation for the Assertion.**

### Final Answer:
- **Both Assertion and Reason are true, and Reason is the correct explanation for Assertion.**