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'.

[EX Q]: Question: The clinical sensitivity of an analytical parameter (test) is defined as: 
 Options:  <1> The mean concentrations of this test in healthy patients. <2> A pathological concentration of the test in the presence of the disease. <3> A pathological concentration of the test in the absence of the disease. <4> A normal concentration of the test in the absence of the disease. <5> A normal concentration of the test in the presence of the disease.
[EX A]: 2

[EX Q]: Question: It is characteristic of the alpha helix: 
 Options:  <1> Present 3.6 amino acid residues per turn. <2> Be levorotatory <3> Be stabilized by intrachain disulfide bridges. <4> Present ionic bonds between amino and ketone groups loaded with peptide bonds. <5> Have the side chains of the amino acids inwards.
[EX A]: 1

[EX Q]: Question: Interactions between selectins and vascular targeins: 
 Options:  <1> They are very strong. <2> They mediate the first phase of the leukocyte / endothelium adhesion. <3> They are permanent. <4> They mediate firm adhesion to the endothelium. <5> They are very intense in the spleen.
[EX A]:
2