Which of these features of Gothic writing is illustrated by the repeated tapping on the speaker's door in Edgar Allan Poe's "The Raven"?

The correct answer would be suspense

The Gothic element there is the horror that ensues after he hears the tapping. The character is alone during a spooky, dreary night, nobody found anywhere, and suddenly there is a mysterious tapping by someone, and it turns out that no-one tapped, which means either madness or ghosts, that are either way both elements of Gothic writing.