Final answer:
The author's tone in the excerpt from Don Quixote is derisive, mocking the protagonist's delusional ambitions and highlighting the absurdity of his quest to become a knight-errant.
Step-by-step explanation:
The narrative voice in the excerpt from Miguel de Cervantes' Don Quixote uses a tone that distances itself from the protagonist's delusion, thereby highlighting the absurdity of his actions in a humorous and critical way. The character of Don Quixote is painted as someone who has lost his understanding and is consumed by an odd fancy to become a knight-errant. This portrayal may lead us to conclude that the tone of the author is derisive.Moreover, the phrase 'the oddest fancy that ever entered into a madman’s brain' indicates a tone that mocks the delusional ambition of the protagonist. This derisive tone is indicative of Cervantes' aim to satirize the unrealistic romantic chivalry of his time, making the main answer to the student's question option 2) derisive.