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: The Baeyer-Villiger oxidation is an important procedure to transform ketones into: 
 Options:  <1> Acids <2> Aldehydes. <3> Esters. <4> Ethers <5> Alquenos
