Which of the following is a mismatched pair?

Options

A. Sternum `" "-` Breast bone
B. Humerus `" "-` Bone in upper arm
C. Pelvis `" "-` Strongest bone
D. Pectoral girdle - Shoulder girdle

Explanation

To determine which of the following pairs is mismatched, we need to analyze each pair provided in the question.

### Step-by-Step Solution:

1. **Identify the First Pair**:
- **Sternum - Breast Bone**: The sternum is indeed referred to as the breast bone because it is located in the chest and serves as a central point for rib attachment.
- **Conclusion**: This pair is correct.

2. **Identify the Second Pair**:
- **Humerus - Bone in the Upper Arm**: The humerus is the long bone in the upper arm, extending from the shoulder to the elbow.
- **Conclusion**: This pair is also correct.

3. **Identify the Third Pair**:
- **Pelvis - Strongest Bone**: The pelvis is not the strongest bone in the body; that title belongs to the femur, which is located in the thigh.
- **Conclusion**: This pair is mismatched.

4. **Identify the Fourth Pair**:
- **Pectoral Girdle - Shoulder Girdle**: The pectoral girdle, also known as the shoulder girdle, supports the upper limbs and is correctly named.
- **Conclusion**: This pair is correct.

5. **Final Conclusion**:
- The mismatched pair is the third one: **Pelvis - Strongest Bone**.

### Answer:
The mismatched pair is **Pelvis - Strongest Bone**.

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