What change in ventilatory pattern is seen during the first stage of moderate exercise?

a. slight decrease in alveolar ventilation within seconds after onset of exercise
b. slight decrease in alveolar ventilation for first two minutes after onset of exercise
c. increase in alveolar ventilation within minutes of onset of exercise
d. increase in alveolar ventilation within seconds after onset of exercise

d. increase in alveolar ventilation within seconds after onset of exercise