Final answer:
The satirical element in the excerpt is Jim and Huck basing their negative opinion of all royalty on their experience with impostors, showcasing Mark Twain's critique of authority and social structures.
Step-by-step explanation:
The satirical element present in the provided excerpt is option D: Jim and Huck are basing their opinion of all royalty on fake kings. The conversation between Jim and Huck reveals their belief that the individuals claiming to be kings are actually rapscallions, pointing to a broader satire on the notion of royalty and how easily people can be deceived. Still, they generalize this idea to all kings, which exaggerates the critique of authority and legitimacy. In the broader context of Mark Twain’s works, this satirical stance is typical, as he often challenges social norms and questions the moral and intellectual integrity of those in power.