<prompt> In body Plethysmography, a person is asked to expire against a closed glottis. Whiat will be the change in the pressure in the lung and the boxIncrease in bothDecrease in bothIncrease in lung decrease in boxDecrease in lung increase in box  <response>: C i.e. Increase in lung decrease in boxBecause of Boyles law P1V1 P2V2, during expiration when lung volume decreases, the pressure inside the lung increases and pressure inside the air tight box decreases because the gas volume in box increases - in body plethysmography in which the subject sits in an air tight chamber. 