Answer:
The answer is A. Sex-linked traits are more often expressed in males because they are typically carried by the X chromosome and they are also typically recessive. Males only inherit one X chromosome, so if the one they inherit is linked to the disease, they will express it no matter what. Females, on the other hand, can be carriers if they inherit one X chromosome with the disease. This is because their other X chromosome can be normal, which would dominate the expression of the disease on their other X chromosome.
