The correct answer is 1. an extended comparison.
A metaphor is a type of comparison - when you are symbolically comparing two or more things (without using words such as like or as), you are using a metaphor. If you extend that metaphor into several lines or stanzas within a poem, then you are using an extended metaphor, which commonly appears in epic poems such as The Odyssey or The Iliad.
They’re all a theme in the novel, but the one that stands out the most would be A, sin.
