<prompt> In an asthmatic patient which of the following pulmonary functions would show the greater improvement on inhaling a bronchodilatorTidal volumeFEV1FEF 25deg-75FVC  <response>: In an asthmatic patient,simple spirometry confirms airflow limitation with a reduced FEV1,FEV1FVC ratio,and PEFpeak ejection fraction.Reversibility is demonstrated by a12 and 200 ml increase in FEV1 15 minutes after an inhaled sho acting beta2 agonistbronchodilator.In some patients,similar response is obtained by a 2 to 4 week trial of oral coicisteroidsprednisolone30-40 mg daily. Reference;:Harrisons Medicine,18the edition,page no:2109. 