<prompt> The following acute respiratory response to ascent to high altitude, there is normalization of blood pH. The mechanism isIncreased erythropoesis leads to increased buffering by hemoglobinIncreased excretion of HCO3 - by the kidneysIncreased levels of 2, 3--DPGRetention of bicarbonate by the kidneys  <response>: The lung response to acute altitude exposure is mainly hyperventilation which, together with elevated hea rate, aims at achieving an adequate supply of oxygen to the tissues. At rest, ventilation increases by firstly increasing the tidal volume, at least up to 3500 m. Ref: guyton and hall textbook of medical physiology 12 edition page number:365,376,377 