In the lungs, residual volume refers to:(A) The volume of gas inspired or expired in an unforced respiratory cycle.(B) The maximum amount of gas that can be expired after a maximum inspiration.(C) The maximum volume of gas that can be inspired after tidal inspiration.(D) The maximum volume of gas that can be expired after tidal expiration.(E) The volume of gas remaining in the lungs after a maximum expiration. Checking your answer...