Task: Question Answering
Input (English): 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.
Output (English): 2