Which rhetorical device establishes a clear contrasting, or opposite, relationship between two ideas?

allusion
antithesis
parallelism
analogy

Let me see if I can help you.
An analogy is a reference to something, so probably not that one.
An antithesis is an opposite, so it could be this.
A parallelism means they are similar, so probably not this one.
An analogy is a comparison of things to show that they are similar, so probably not this one either.

That makes the most logical choice B. Antithesis

I would feel shocked by the unkind humor and think shame on him. The sonnet 130 more rude than 138 but also more humorous. I am unsure what you meant by voltas.