This is supposed to be science
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. Camels still have the adaptation because once a species evolves a trait, it can never be lost.
C. Each generation of camels must develop the adaptation or the camels won't be able to survive in the desert.
D. Camels have retained the adaptation because they still want the ability to survive with limited water.