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: If you want to study the efficacy and safety of a new cytostatic for a specific oncological process and, at the same time, contrast the efficacy that adds a new monoclonal antibody to this treatment, what would be the most appropriate study design?
Options: <1> Parallel test. <2> Cross test <3> Factorial test. <4> Sequential test. <5> Test of n = 1.
A:
3