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 biological cycle of Trichinella spiralis is of the following type:
Options: <1> Stenoxene <2> Optional. <3> Triheteroxene <4> Autoheteroxene <5> Heterogonico.
Solution:
4