Medicine Diagnostic criteria for bronchial asthma is bronchospasm which is reversible with 2 puffs of beta adrenergic agonist with increase in FEV1 by at least A 5% B 10% C 15% D 20% 💡 Explanation Diagnostic criteria for bronchial asthma is bronchospasm which is reversible with 2 puffs of beta adrenergic agonist with increase in FEV1 by at least ✓ Correct Answer: C. 15%