Which of the following is true about ventilation-perfusion coupling?

in alveoli where ventilation is inadequate, the partial pressure of oxygen is high

terminal arterioles dilate in areas where the partial pressure of oxygen is low

blood is shifted towards alveoli with low partial pressure of oxygen to enhance oxygen pick-up from lungs

in alveoli where ventilation is maximal, the partial pressure of oxygen is low

terminal arterioles dilate in areas where the partial pressure of oxygen is high