Use the Following Information to Answer the Questions Below

Use the following information to answer the questions below.
Labrador retrievers are black, brown, or yellow. In a cross of a black female with a brown male, results can be either all black puppies, 1/2 black to 1/2 brown puppies, or 3/4 black to 1/4 yellow puppies.
-How many genes must be responsible for these coat colours in Labrador retrievers?

A) 1
B) 2
C) 3
D) 4
E) 5