<prompt> If FEV1 is 1.3 L, FVC is 3.1 L in an adult man, the pattern is suggestive of:Normal lung functionRestrictive lung diseaseObstructive lung diseaseNone of the above  <response>: Obstructive lung disease:- - FEV1 is reduced due to obstruction of air escaping from the lungs. Thus, FEV1 FVC ratio will be reduced. Restrictive lung disease:- - FEV1 and FVC are equally reduced due to fibrosis or other lung pathology . Thus,FEV1FVC ratio -normal or even increased. In this question, a ratio of 1.33.1 is about 40 in contrast to a normal of 80. 