Answer:
The correct answer is option d. "Humans share a deep evolutionary ancestry with other animals that can be seen in reappearing atavisms or body parts that no longer seem to have a function".
Explanation:
A vestigial organ or vestigial structure is an anatomical feature that no longer seems to have a function, but they used to serve a purpose in an ancient form of an organism in the past. Atavisms, are vestigial organs that seem to reappear after having been lost through evolutionary change. Charles Darwin's studies on the subject made him conclude that humans share a deep evolutionary ancestry with other animals that can be seen in reappearing atavisms or body parts that no longer seem to have a function. He published his studies on human vestigial organs and atavisms in his book "The Descent of Man, and Selection in Relation to Sex".