<prompt> True regarding changes in respiratory system in pregnancyRespiratory rate increaseVital capacity remains unchangedTidal volume increaseTotal lung capacity increases  <response>: Respiratory ratemin 15 15 UnaffectedVital capacity 3200 3300 Almost unchangedTidal volume ml 475 675 40Residual volume ml 965 765 -20Total lung capacity 5000 4750 -8 