Detailed Instructions: In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.
Problem:Question: The response trend is an important source of error that diminishes the quality of:
Options: <1> Projective techniques. <2> The semi-structured interview. <3> The methodology of the Observation. <4> The Self-reports. <5> The Objective Techniques.
Solution:
4