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 enolate ions undergo conjugate addition to α, β-unsaturated aldehydes and ketones, a reaction known as: 
 Options:  <1> Addition of Michael. <2> Addition of Prins. <3> Transposition of Cope. <4> Radical addition. <5> Transposition of Beckman.
