Answer A) "Because though he is filled with paler blood, he hates the sort of noble his father is and works against nobles to thwart him and free his fellow commoners. He will not be a slave no matter how gilded the yoke."
Answer B) "Because unlike the father, the son will never bend knee to a noble. And the father seeks to make the son pay for what he sees as crimes."
Answer C) "the father seeks a treasure in his possession, and would be willing to kill him to claim it."
Answer D) "Because, he is not ready to meet you yet."