Which aspect of psychological suspense dominates the passage?

plot developed through fantasy
plain and simple writing style
heroic, admirable protagonists
emphasis on madness

"down-steadily i crept" < that part of the poem the pit and pendulum

The aspect of psychological suspense that dominates the passage is emphasis on madness

Explanation:

From the excerpt "Down—steadily down it crept. I took a frenzied pleasure in contrasting its downward with its lateral velocity. To the right—to the left—far and wide—with the shriek of a dam ned spirit! to my heart with the stealthy pace of the tiger! I alternately laughed and howled, as the one or the other idea grew predominant."

The poem "The pit and pendulum" by Edgar Allan Poe, shows in this excerpt how the narrator loses his mind after being under the pressure of the torture and uncertainty of his own destiny in that pit, he even started to see things around him and to create mental images.