Which of the following oxides is amphoteric?

An amphoteric oxide is a type of oxide that can act as both an acid and a base. It has the ability to react with both acids and bases to form different compounds. Carbon(II) oxide (CO) is not amphoteric. It is a neutral oxide and does not exhibit acidic or basic properties. Nitrogen(IV) oxide (NO2) is not amphoteric either. It is a non-metal oxide and typically acts as an acidic oxide, reacting with water to form nitric acid. Lead(II) oxide (PbO) is amphoteric. It can react with both acids and bases. With acids, it acts as a base and forms salts. With bases, it acts as an acid and forms plumbates. Calcium oxide (CaO) is not amphoteric. It is a basic oxide and reacts with acids to form salts. Therefore, among the given options, lead(II) oxide is the amphoteric oxide.