Probably because of the anime fans who are weirdos tbh
They are frozen and he cannot feel them. He is in danger of losing them to frostbite
Well, it's not A. Mary did not let hm accept the disease.
It's not B-he told her about his mother (I think).
It's not D because she is brought to live there.
It's C because she doesn't let him accept his illness and ends up helping him.