The camel is a desert animal that possesses the ability to survive for long periods of time without water. camels walking in a desert

Which of the following statements best explains why camels still have this adaptation?
A.
The adaptation allows camels to survive long enough to reproduce, so it is passed from one generation to the next.
B.
Each generation of camels must develop the adaptation or the camels won't be able to survive in the desert.
C.
Camels have retained the adaptation because they still want the ability to survive with limited water.
D.
Camels still have the adaptation because once a species evolves a trait, it can never be lost.

BTW IT SCIENCE I CAN FIND IT