The correct answer is C.
In this excerpt from chapter 23 of "The Adventures of Huckleberry Finn" humor is achieved thought the image of the king performing.
The king, the ruler of the country, a man of high esteem and regard is presented naked, pracing on all fours, covered in paint of different colours all over his body. This ridiculous and degrading image of such an important man is the source of humor in this passage.