Task: Question Answering
Input (English): Question: The reactivation of a latent cytomegalovirus in an immunosuppressed patient can lead to a severe systemic picture. How would the ethological diagnosis? 
 Options:  <1> Detecting the specific IgG in the serum. <2> By urine culture in an advanced cell line. <3> By chain reaction of quantitative polymerase in the blood. <4> By detection of antigen in the urine. <5> By detection of specific IgM in the serum.
Output (English): 3