Final answer:
The genotype of a person with a non-functional H gene is hh, resulting in the O blood type.
Step-by-step explanation:
The genotype of a person who has a non-functional H gene is A) hh. The H gene is responsible for the production of the H antigen on the surface of red blood cells. If this gene is non-functional, it means that the person will not have the H antigen, leading to the O blood type.