Final answer:
The lungs are not part of the upper respiratory system; they belong to the lower respiratory system which is responsible for gas exchange. So, the correct answer is option 2.
Step-by-step explanation:
The part of the respiratory system that is not considered a component of the upper respiratory system is the lungs. The upper respiratory system includes the nose, pharynx, nasal cavity, and other structures like the larynx and trachea up to the point of the epiglottis.
The lungs, which contain the bronchi, bronchioles, and alveoli, are actually part of the lower respiratory system. The upper respiratory system is responsible for filtering, warming, and moistening the air we breathe, while the lower respiratory system is involved in gas exchange.
So, the correct answer is option 2.