Definition: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Input: Question: In a patient with asthma symptoms, diagnostic confirmation of the disease will be made first by:
Options: <1> The finding of a reversible obstruction of air flow in spirometry. <2> A positive allergic skin test. <3> An increase in the number of eosinophils in the induced sputum. <4> The elevation of nitric oxide in exhaled air (FENO). <5> The presence of a specific IgE in blood to an aeroallergen.
Output:
1