The antonym of “Impertinent” is:

“Impertinent” means rude or disrespectful, especially in a way that is inappropriate to the situation. Its antonym, “polite,” refers to courteous and respectful behavior. In English vocabulary, identifying antonyms requires understanding the core meaning of the word, and polite directly opposes impertinent’s negative connotation. Options A (rude, a synonym), C (arrogant, similar in tone), and D (bold, unrelated) do not provide the opposite meaning, confirming B as the correct answer.