Which part of the respiratory system is in the upper respiratory tract?

The upper respiratory tract includes structures such as the nose, nasal cavity, pharynx, and larynx. These structures are responsible for filtering, warming, and humidifying the air. The lower respiratory tract comprises the trachea, bronchi, bronchioles, alveolar ducts, and alveoli. Bronchioles, alveolar ducts, and alveoli are all part of the lower respiratory system, involved in gas exchange. Therefore, the correct answer is 'None of the above' as none of the listed options are part of the upper respiratory tract.