What Is the Primary Regulator of the Magnitude of Alveolar

What is the primary regulator of the magnitude of alveolar ventilation under normal circumstances?

A) the H⁺ concentration in the brain extracellular fluid, which is monitored by central chemoreceptors
B) The PO₂ of the arterial blood, which is monitored by central chemoreceptors
C) The PO₂ of the arterial blood, which is monitored by peripheral chemoreceptors
D) the H⁺ concentration in the arterial blood, which is monitored by central chemoreceptors
E) stretch receptors in the lung