What is the most effective way to combine sentence 12 and 13 and make the meaning more clear? Sentences: (12) We all laughed. (13) He had to be joking!

A. We all laughed and we realized he had to be joking.
B. We all laughed, we knew he was joking.
C. We all laughed because we thought he had to be joking.
D. We all laughed, of course he was joking. ​

The main themes of the play are: fate and free will with the inevitability of oracular predictions is a theme that often occurs in greek tragedies the conflict between the individual and the state similar to that in sophocles’ “antigone” and   people’s willingness to ignore painful truths both oedipus and jocasta clutch at unlikely details in order to avoiding facing up to the inceasingly apparent truth and sight and blindness the irony that the blind seer tiresius can actually “see” more clearly than the supposedly clear-eyed oedipus, who is in reality blind to the truth about his origins and his inadvertent crimes.

Not sure what you are asking for but this is a persuasive essay.