Task: Question Answering
Input (English): Question: What does the intersessional sampling used in observation techniques refer to: 
 Options:  <1> To the registration of relevant information between sessions. <2> To the periodicity, number and criteria of start-end of the sessions. <3> To the successive rounds of observation of the subjects to observe. <4> To the temporary selection and its interval or partial modality. <5> To the record of focal events that occur between sessions.
Output (English): 2