In describing his marriage to his former sister-in-law, Claudius pairs a number of opposites such as "defeated joy," "mirth in funeral," and "dirge in marriage." This language suggests that Claudius views his marriage to Gertrude as an attempt to __________.
A) encourage Hamlet to return to his studies in Wittenburg
B) seek approval from the court for his royal decisions
C) balance the bad with the good in Denmark
D) avoid having to go to war with Norway

Claudius is the brother of a king who has just died. Denmark hasn't finished mourning his beloved king (bear in mind that the King in those days was the representation of God on Earth, so it was someone remarkably important) when Claudius marries Gertrude the late King's wife, in other words, he marries his sister in law. So, this is why there is a mixture of feelings, you have just had a funeral and now a wedding.

Claudius needs to earn the trust and the approval of the Court because his actions may look suspicious and he doesn't want anyone to start thinking about the true intentions that he had and that he has. So, before starting to talk about how to deal with the kingdom, he sort of justifies his actions in front of the court, explaining to them that although he is still sad, he is also happy that he has decided follow the advice of the court to make his sister in law, his wife.

Claudius needs to drive all suspicions aways from him, because he is the one that killed the king, he achieves this by seeking the approval of the court.