Which of the following is vestigeal organ in humans

Options

A. Ear pinna
B. Nictitating membrane
C. Mammary glands in males
D. All of the above

Explanation

**Step-by-Step Solution:**

1. **Understanding Vestigial Organs:**
- Vestigial organs are those that were once functional in our ancestors but have lost their original function over time due to evolution. They are often reduced in size and do not significantly impact the organism's survival or reproduction.

2. **Identifying the Options:**
- The options provided are:
- Earpina
- Nictitating membrane
- Mammary glands in males
- All of the above

3. **Analyzing Each Option:**
- **Earpina:**
- In our ancestors, the earpina (the outer part of the ear) had muscles that allowed them to move their ears to better locate sounds. In humans, these muscles are present but non-functional, making the earpina a vestigial organ.
- **Nictitating Membrane:**
- This is a translucent membrane that was used by some animals to protect and moisten their eyes. In humans, it is greatly reduced and no longer serves its original purpose, classifying it as a vestigial structure.
- **Mammary Glands in Males:**
- In male humans, mammary glands are present but do not serve any reproductive function as they do in females. They are remnants from our evolutionary past, making them vestigial as well.

4. **Conclusion:**
- Since all the listed options (earpina, nictitating membrane, and mammary glands in males) are considered vestigial organs in humans, the correct answer is **"All of the above."**

**Final Answer:**
The vestigial organs in humans include earpina, nictitating membrane, and mammary glands in males. Therefore, the answer is **"All of the above."**

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