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 hydroxy acids can be esterified intramolecularly by forming: 
 Options:  <1> Lactams <2> Nitrones. <3> Imidas <4> Carbamates. <5> Lactones.
Output:
5