Certain species of blind fish living in perpetual darkness in the ocean depths have evolved from ancestors that could see. Research indicates that the brain centers for vision in these fish is degenerating, whereas the brain centers controlling other senses are enlarging. What might be the MOST probable reason for the loss of vision in these fish?' A.
exposure to mutagens that caused the loss of vision

B.
progressive selection of genetic variants in the population leading to blindness as an evolutionary adaptation

C.
infection by cave-dwelling microorganisms that has led to degeneration of the eyes

D.
extreme high pressure at the ocean depths causing a deterioration of vision