Which of the choices below determines the direction of respiratory gas movement? a. pulmonary ventilation
b. transport of respiratory gases
c. external respiration
d. pulmonary respiration

a. pulmonary ventilation

Explanation:

Pulmonary ventilation: In biology, the term "pulmonary ventilation" is also referred as "breathing" and is described as a phenomenon of moving air out and into an individual's lungs. Generally, air enters the "respiratory system" via nasal cavity and mouth, and then it passes through the "pharynx" and then  the "larynx" and lastly to the "trachea" that enters the "chest cavity" of an individual.

In the question above, the correct answer is option A.

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