Which of the following describes the journey of a molecule of oxygen from the pharynx to an alveolus?

A)pharynx to trachea to bronchus to bronchiole to alveolus
B)pharynx to trachea to bronchiole to bronchus to alveolus
C)pharynx to bronchiole to bronchus to trachea to alveolus
D)pharynx to bronchus to bronchiole to trachea to alveolus