Task: Question Answering
Input (English): Question: A complication of transplantation of hematopoietic precursors is: 
 Options:  <1> Common variable immunodeficiency. <2> Graft-versus-host disease. <3> Immunodeficiencies in complement components. <4> The lack of NK lymphocytes. <5> Chronic granulomatous disease.
Output (English): 2