The Himalayan Allele in Rabbits Produces Dark Fur at the Extremities

The Himalayan allele in rabbits produces dark fur at the extremities of the body-on the nose, ears, and feet.The dark pigment develops, however, only when a rabbit is reared at a temperature of 25°C or lower; if a Himalayan rabbit is reared at 30°C, no dark patches develop.What does this exemplify?

A) Dominance
B) Discontinuous characteristic
C) Genetic imprinting
D) Phenocopy
E) Temperature-sensitive allele