The answer is C. fire barrier
I believe that the answer would be A.) Empathy.
Usher's madness begins to increase because he can hear the sound of Madeline below.
Even though his sister is buried in the basement, he can constantly hear her scratching her coffin. He was tortured by these sounds until the protagonist came to visit him so he could share his troubles with him. Usher is afraid of his 'undead' sister and of dying himself, which is why he grows crazier and crazier by the day, until he is finally killed by his own sister in the end.
Answer:
why the lowest level of an energy pyramid contains the most organisms and the highest level of an energy pyramid contains the least organisms.
Explanation:
The first sentence of your answers
