A decrease in Carbon Dioxide (CO2) in your blood (hypocapnia) will lead to:

CO2 is the PRIMARY driver of respiration. When CO2 DECREASES (hypocapnia — e.g., during hyperventilation), the respiratory drive is REDUCED, leading to DECREASED tidal volume and respiratory rate (the body slows breathing to allow CO2 to build back up). Increased tidal volume (A) would occur with HIGH CO2. Hypocapnia causes vasoconstriction (not vasodilation — D wrong) and cerebral vasoconstriction (causes lightheadedness in hyperventilation). B is the best answer among options.