Which of the following is not vestigeal organ in human beings?

Options

A. Rudimentary ear muscles and third molars (wisdom teeth), body hair
B. Coccygeal tail vertebrae and scalp muscles
C. Vermiform appendix and nictitating membrane of the eye
D. Ear pinna, patella, olecranon process

Answer

To determine which of the following is not a vestigial organ in human beings, we need to first understand what vestigial organs are. Vestigial organs are those that are present in the body but do not have any apparent function. They are remnants of structures that were functional in our ancestors but have lost their utility through the process of evolution.

Let's analyze the options provided:

1. **Rudimentary ear muscles and third molar (wisdom teeth)**:
- Rudimentary ear muscles are considered vestigial as they are remnants of muscles that were used to move the ears in our ancestors.
- Third molars, commonly known as wisdom teeth, are also considered vestigial because they were useful for our ancestors who had a different diet requiring more chewing power.

2. **Body hair**:
- Body hair is not considered vestigial. While it may serve less function in modern humans compared to our ancestors, it still plays roles in protection and sensory functions.

3. **Coccygeal tail vertebrae**:
- The coccyx (tailbone) is a vestigial structure as it is a remnant of a tail that was present in our primate ancestors.

4. **Scalp muscle**:
- Scalp muscles are not vestigial; they are functional and allow for movement of the scalp.

5. **Vermiform appendix and nictitating membrane of the eye**:
- Both the vermiform appendix and the nictitating membrane (third eyelid) are considered vestigial organs as they have lost their original functions in humans.

6. **Ear pinna, patella, olecranon process**:
- The ear pinna (outer ear) is functional for hearing.
- The patella (kneecap) is important for knee joint function.
- The olecranon process is a part of the ulna that serves a functional role in arm movement.

Based on this analysis, the option that is **not** a vestigial organ is **body hair**.

### Final Answer:
**Body hair is not a vestigial organ in human beings.**