Answer:
a. It produces shivers down the spine, or a feeling of unease.
Step-by-step explanation:
Washington Irving's "The Adventure of the Mysterious Picture" is a gothic story where the characters staying in the house were talking, sharing stories of haunted places. And the host of the house had 'in jest' said that one of the rooms was haunted, so the her of the nigh will be revealed the next morning after they had all spent their nights in their own allotted rooms.
The passage in the question gives the details of the narrator's room. he had seen a picture hanging in his allotted room and had been unable to ignore it. He felt all sorts of uneasiness, unable to even sleep properly, constantly thinking there's someone hovering above him. The tone of the passage gives us a feeling of horror, sending shivers down the spine, making us feel uneasy. This passage makes it possible that the room was indeed haunted, making even us, the readers, scared of what will happen and what really is the picture about. It spreads a feeling of uncomfortable, and scared feeling in the narrator and the readers altogether.