Final answer:
Option (C), Breeding a rabbit homozygous for black fur (BB) with one homozygous for white fur (bb) results in all offspring having a heterozygous genotype (Bb) and a gray phenotype due to incomplete dominance.
Step-by-step explanation:
When a rabbit that is homozygous for black fur (an incomplete dominant trait) is bred with a rabbit that is homozygous for white fur, incomplete dominance is displayed. The genotype of the black fur rabbit can be represented as BB, while the white fur rabbit has a genotype of bb.
In incomplete dominance, the heterozygous offspring (Bb) will exhibit a blending of the two traits. Therefore, all offspring from this cross will have the genotype Bb and display an intermediate gray phenotype, that is neither purely black nor purely white.