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'.

Example Input: Question: The set of social mechanisms whose function is the transformation of specialized products in the form of health services for society, is called system: 
 Options:  <1> Sanitary. <2> Social. <3> Social insurance. <4> Liberal. <5> From the market
Example Output: 1

Example Input: Question: Sodium metal reacts violently with water because Na: 
 Options:  <1> Oxidize the water to oxygen, and the reaction is very exothermic. <2> It reduces the water to hydrogen, and the reaction is very exothermic. <3> Oxidizes the water to oxygen, and when a gas is generated, the entropy increases enormously. <4> It reduces the water to hydrogen, and the reaction is very endothermic. <5> It combines with water giving rise to an explosive hydride.
Example Output: 2

Example Input: Question: Enzymatic regulation by phosphorylation: 
 Options:  <1> It is reversible. <2> It requires enzymes that directly introduce the Pi. <3> Introduce the Pi into acidic and basic amino acids. <4> Always activate enzymes. <5> It is carried out by phosphatases.
Example Output:
1