Part of the body having a single pair of bones is

Options

A. (1) pelvic girdle
B. (2) external ear
C. (3) wrist
D. (4)lower jaw

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a part of the body that has a single pair of bones. This means we are looking for a specific anatomical structure where only one distinct pair of bones exists.

2. **Analyzing the Options**:
- **Option A: Pelvic Girdle**: The pelvic girdle consists of three bones: the ilium, ischium, and pubis. However, these bones are paired, meaning there are two of each type (left and right). Therefore, this option does not represent a single pair of bones.
- **Option B: External Ear**: The external ear contains multiple small bones (ossicles), specifically three: the malleus, incus, and stapes. This option does not fit the criteria of having a single pair of bones.
- **Option C: Wrist**: The wrist is composed of multiple carpal bones, which do not form a single pair. Thus, this option is also incorrect.
- **Option D: Lower Jaw**: The lower jaw (mandible) is a single bone, but it is not a pair since there is only one mandible in the body.

3. **Identifying the Correct Answer**: After analyzing all the options, it is clear that none of the options provided fit the criteria of having a single pair of bones. However, if we consider the pelvic girdle as having a functional pair (left and right), it can be interpreted as the closest answer, but it is important to note that it consists of multiple bones.

4. **Conclusion**: The best option that aligns with the question's requirement of having a single pair of bones is **Option A: Pelvic Girdle**, as it is the only structure that can be interpreted to have a paired arrangement.

### Final Answer:
**Pelvic Girdle**

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