Human appendix, coccyx and nictitating membrane of the eye are:

Explanation

Vestigial organs are structures in the body that have lost or greatly reduced their original function in the course of evolution. These organs may have had a more significant purpose in the ancestors of a species, but in the current form of the organism, they serve little or no function. The human appendix, coccyx (tailbone), and the nictitating membrane (also known as the third eyelid, found in some animals) are considered vestigial organs: - Appendix: It is a small, finger-like projection located at the beginning of the large intestine. In humans, it appears to have lost its original digestive function and currently does not play a significant role in the digestive system. - Coccyx: The coccyx is the remnant of a tail-like structure that was more prominent in some of our evolutionary ancestors. In humans, it no longer serves a functional tail-like purpose. - Nictitating Membrane: In humans, this is often referred to as the "vestigial plica semilunaris." It's a small fold of tissue in the inner corner of the eye. In some animals, like birds and reptiles, it can be drawn across the eye for protection. In humans, it has mostly lost this function. Therefore, option a is correct.