Final answer:
The correct genotype for a person with hemophilia is XhY. Hemophilia is a sex-linked disorder affecting clotting factor synthesis, requiring males to have only one allele on the X chromosome to express the disease, while females must have two. The correct option is 3).
Step-by-step explanation:
A person with hemophilia would have the correct genotype XhY (option 3). Hemophilia is a genetic disorder characterized by inadequate synthesis of clotting factors and is most commonly a sex-linked condition, particularly linked to the X chromosome. Since males have only one X chromosome (XY), the presence of a single allele for hemophilia (Xh) suffices for the condition to be expressed. In contrast, females have two X chromosomes (XX) and would need to inherit two mutated genes, one from each parent (XhXh), to express the disease. The rarity of hemophilia in females is due to the requirement of having both X chromosomes carry the mutation, which is far less common as they could be carriers with just one mutated X chromosome without expressing the disease (XHXh).