Q: 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'.
Question: In a quasi-experimental design:
Options: <1> There is no specific intervention by the researcher on the independent variable or treatment. <2> Spontaneous behavior is studied in natural situations. <3> It constitutes the maximum degree of intervention and internal control. <4> Study groups can not be organized by random assignment. <5> It represents the maximum degree of naturalness and the minimum internal control.
A:
4