Assertion` :-`First seven pairs of ribs are called true ribs.
Reason `:-` They are attached to the thoracic vertebrae dorsally and ventrally connected to the sternum with the help of hyaline cartilage.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion .
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

### Step-by-Step Solution:

1. **Understanding Ribs**: The human ribcage consists of 12 pairs of ribs. These ribs are categorized into three types based on their attachment to the sternum.

2. **True Ribs**: The first seven pairs of ribs are known as "true ribs." They are called true ribs because they are directly attached to the sternum via costal cartilage.

3. **Attachment of Ribs**: The true ribs are connected dorsally (at the back) to the thoracic vertebrae and ventrally (at the front) to the sternum through hyaline cartilage. This connection allows for flexibility and expansion of the ribcage during breathing.

4. **Analyzing the Assertion and Reason**:
- **Assertion**: "First seven pairs of ribs are called true ribs." This statement is true.
- **Reason**: "They are attached to the thoracic vertebrae dorsally and ventrally connected to the sternum with the help of hyaline cartilage." This statement is also true and correctly explains why the first seven pairs are called true ribs.

5. **Conclusion**: Since both the assertion and reason are true, and the reason correctly explains the assertion, the correct option is that both the assertion and reason are true, and the reason is a correct explanation of the assertion.

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

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