NEET 2005 Biology question

A woman with normal vision, but whose father was colour blind, marries a colourblind man. Suppose that the fourth child of this couple was a boy. This boy :

• (A)must have normal colour vision
• (B)will be partially colourblind since he is heterozygous for the colourblind mutant allele
• (C)must be colourblind
• (D)may be colourblind or may be of normal visionCorrect