Definition: 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: What two non-protein amino acids participate in the urea cycle ?: 
 Options:  <1> Proline and hydroxyproline. <2> Ornithine and citrulline. <3> Alanine and arginine. <4> Oxalacetate and malate. <5> Serine and GABA.
