Task: Question Answering
Input (English): Question: P. L. is a patient with frequent urinary infections. When explaining the possible causes of the same will comment that a risk factor is: 
 Options:  <1> The presence of urinary stones. <2> The intake of substances that acidify the urine. <3> The increase of leukocytes in urine. <4> The saturation of urine by calcium salts. <5> The emission of urine every 2 or 3 hours.
Output (English): 1