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'.
Input: Question: The recombinant DNA is:
Options: <1> A DNA molecule that activates heterologous recombination. <2> A precursor messenger RNA molecule. <3> A DNA molecule composed of segments covalently linked from two or more sources. <4> A diploid DNA molecule. <5> A multienzyme complex of DNA polymerases covalently linked.
Output:
3