The correct option is C.
Incomplete dominance is said to occur when two allele are crossed and neither of them is dominant over the other. In this type of situation, the two traits carried by the alleles usually exist together. A good example of this is the pink coloured rose. When a red rose flower and a white rose flower are crossed, they sometime yield pink colour rose flower, which expresses neither of the two parents colour. Incomplete dominance usually give rise to offspring that have intermediate properties compared to the two parents.