Answer is C (Decreased FEVI/FVC): Interstial lung diseases produce a restrictive pattern on Pulmonary function testing and are characterized by a normal or elevated FEVIFVC ratio which is greater than 0.7 FEV and FVC are both reduced in interstitial lung disease but the decrease in FEVI is in propoion to decrease in FVC and hence the FEVI/FVC ratio is normal (or increased)