Which one of the following pairs of structures is correctly matched with their description?

Options

A. Tibia and fibula - Both form parts of knee joint
B. Joint between atlas and axis - Pivot joint
C. Shoulder joint - Ball and socket type of joint and elbow joint
D. None of these

Explanation

To solve the question of which pair of structures is correctly matched with their description, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the Structures:**
- The question provides pairs of structures and their descriptions. We need to evaluate each pair.

2. **Evaluate the First Pair (Tibia and Fibula):**
- Tibia and fibula are bones in the lower leg.
- The description states they form part of the knee joint.
- **Analysis:** The knee joint is formed by the femur and tibia, with the patella acting as the kneecap. The fibula does not contribute to the knee joint.
- **Conclusion:** This pair is **incorrect**.

3. **Evaluate the Second Pair (Atlas and Axis):**
- Atlas and axis are the first two cervical vertebrae in the spine.
- The description states they form a pivot joint.
- **Analysis:** The joint between the atlas and axis indeed allows for rotational movement of the head and is classified as a pivot joint.
- **Conclusion:** This pair is **correct**.

4. **Evaluate the Third Pair (Shoulder Joint):**
- The shoulder joint is described as a ball and socket joint.
- **Analysis:** This is accurate as the shoulder joint allows a wide range of motion due to its ball and socket structure.
- However, the description incorrectly mentions the elbow joint instead of the shoulder joint.
- **Conclusion:** This pair is **incorrect**.

5. **Final Conclusion:**
- The only pair that is correctly matched with its description is the second pair: the joint between atlas and axis is a pivot joint.

### Answer:
The correct pair of structures matched with their description is: **Joint between atlas and axis - Pivot joint.**

---