The correct option is B Humayun
Humayun died by falling from the steps of library. On the evening of 24th January , 1556, king Humayun was sitting on the roof of his library situated in that group of the buildings known as Din Panah and was subsequently called Sher Mandal. He was talking to some of his distinguished nobles and astrologers and it was arranged to hold a durbar at the time of the appearance of the planet Venus. He got up in order to descend the steep stairs and go to attend the evening prayer. His slipped and he fell down the stairs and fractured his skull and he died on January 26, 1556.