A 28-year-old woman on oral contraceptives develops tachypnea and reports dyspnea. A ventilation/perfusion scan is ordered to check for pulmonary thromboemboli. Which of the following best explains why, as she takes in a normal inspiration, more air goes to the alveoli at the base of the lung than to the alveoli at the apex of the lung?
a. The alveoli at the base of the lung have more surfactant.
b. The alveoli at the base of the lung are more compliant.
c. The alveoli at the base of the lung have higher ratios.
d. There is a more negative intrapleural pressure at the base of the lung.
e. There is more blood flow to the base of the lung.