The answer is; C.
Hemophilia, even based on the description in the question, is a genetic disease. This is caused by a faulty gene that codes for a faulty factor VIII protein involved in the clotting of blood. It is a sex-linked gene hence means it is carried in the X chromosome. Girls are less likely to express the disease because they have 2 X chromosomes hence unless both X chromosomes carry the defective gene, they will only be careers.