Vestigial organs are structures in organisms that have lost most or all of their original function through evolution, serving as remnants of ancestral traits. The question asks which option is NOT a vestigial organ.
The correct answer is Eyelids. Eyelids are fully functional and essential for protecting the eye from foreign objects, keeping it moist, and regulating light exposure. They play a vital role in maintaining eye health and vision, thus they are not vestigial.
Conversely, the other options are considered vestigial: Wisdom Teeth (A) often cause problems due to lack of space and reduced chewing function in modern diets. The Pinna (B), or external ear, has minimal functional significance in humans compared to many animals. The Vermiform Appendix (D) is a small, finger-shaped pouch whose primary function in humans is largely lost or debated, and it can be removed without significant adverse effects.