The right answer is letter b: the houses in both passages are described as having an air of rot, gloom and loneliness.
Poe's character describes Mr. Roderick Usher's house as one he cannot help to consider a "melancholy view" where "there was an iciness, a sinking, a sickening of the heart" . Said house caused an "insufferable gloom" in the observer's spirit.
In a similar thread of thought, Bierce's tale about the Manton house describes its looks as sufficient to affirm it is "haunted". He describes the house as "slowly falling into decay" as "cobwebs weave in the angles of the walls like strips of rotting lace..." all while standing "a little way off the loneliest reach of the Marshall and Harriston road".