Final answer:
The passage from Mark Twain's 'Adventures of Huckleberry Finn' which features Huck's rhetorical questioning about the value of doing right versus wrong exhibits a mocking tone through its satirical commentary on moral action in society.
Step-by-step explanation:
The part of the passage that best conveys a mocking tone is the quote from Mark Twain's Adventures of Huckleberry Finn, where Huck questions the societal valuation of moral actions with irony: "What's the use you learning to do right, when it's troublesome to do right and isn't no trouble to do wrong, and the wages is just the same?" This rhetorical question uses satire to criticize the often flawed moral compass of society by highlighting how doing the right thing is sometimes unrewarded while wrongdoing faces no consequence, reflecting a deep societal irony in a seemingly innocuous observation.