This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
Reduced FEV 1, Normal FVC and FEV 1/FVC ratio less than 0.7 .which is reversible with bronchodilator s is consistent with 
Select and explain. 
A. Bronchial Asthma, B. Hypersensitivity penumonitis, C. Sarcoidosis, D. Polyaeritis nodosa
A: Bronchial Asthma
Answer: A: Bronchial Asthma 
Explanation: In Asthma FEV1(forced expiratory volume in 1 second), FVC(forced vital capacity, is the total volume exhaled), FEV1/FVC decreases. To daignose Asthma: Compatible clinical history plus either : 1)FEV1>12% increase following administration of a bronchodilator or glucocoicoids. 2)FEV1>15% decrease after 6min of exercise 3)>20% diurnal variation on >3days in a weeks on PEF(peak expiratory volume). Reference : Davison, 23rd Edition, page no : 569,555