Night-blindness is a genetic disorder in which a person’s vision is unusually poor under low light levels. The diagram illustrates how night-blindness is passed on through three generations of a family. Couple 4 and 5 are waiting for their second child, individual 7. What is the probability that individual 7 will be male and will also have night-blindness as his phenotype?
- A$0.500$
- B$0.300$
- C$0.250$
- D$0.125$