You would need to introduce a list.
For example you could have: My shopping list contains of; milk, bread, and yogurt.
Another purpose is to separate clauses.
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.
The right answer is "A. The clergy "
You should be referring to the quote from "The Canterbury Tales" where the word gold is used to represent the clergy in all its purity that leaves it in such a high standard that nothing can reach it, just as gold can not be attained by rust.
The event which is associated with the peripeteia (or turn of events) in the play is Teiresias prophecy. It changed the whole course of the drama afterwards.