In a particular species of mammal, black hair (b) is dominant to green hair (b), and red eyes (r) are dominant to white eyes (r). when a bbrr individual is mated with a bbrr individual, offspring are produced in a ratio of 5 black hair and red eyes : 5 green hair and white eyes : 1 black hair and white eyes : 1 green hair and red eyes. which of these explanations accounts for this ratio?