When a Gene Carrying a Third Photopigment Was Introduced into Photoreceptors

Multiple Choice

When a gene carrying a third photopigment was introduced into photoreceptors of adult male squirrel monkeys with dichromatic vision, the monkeys

A) gained the ability to discriminate short-wavelength stimuli (blue) from long-wavelength stimuli (not blue) .
B) lost the ability to discriminate short-wavelength stimuli (blue) from long-wavelength stimuli (not blue) .
C) gained trichromatic vision.
D) gained yellow-blue discrimination.