Answer:
A
Explanation:
They create a mood of despair
Milton is using the nature of darkness to indicate evil, the opposite of God (or "light").
For this reason the fire of Hell has no light. (God and heaven, however, are always described in terms of light.)
As a result, Milton's vision of hell is so dark that it is "darkness visible" -- meaning it is visible evil. In forsaking God, Satan and his companions have forsaken all light as well.
The quotation: "She was a sweet, pretty thing and he'd have walked the world over to get her a blade o' grass she wanted." Because it is an exaggerated metaphorical statement.
I want to say B, but don't quote me on it