The courtier that wrote a guide that describes how a courtier should act while serving at court was Baldassare Castiglione, so option A is correct. Castiglione wrote “The book of the Courtier” and it was published in 1528. The book includes rules of etiquette, and how a courtier should behave, especially at royal courts. The book summarizes the manners and morals that the perfect courtier is expected to have.
The rest of the options are incorrect since none of then wrote a book of manner or etiquette at court.
