Which of the following is an example of incomplete dominance?
a. in a cross between tall plants and short plants, half the offspring are tall and half the offspring are short.
b. a cross between a black mouse and a white mouse produces a gray mouse.
c. a blue-eyed child has one blue-eyed parent and one brown-eyed parent.
d. a cross between a white cow and a red bull produces a calf with white hairs and red hairs.