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: Which of the following drugs used in the treatment of osteoporosis acts by binding to the RANK ligand? 
 Options:  <1> Alendronate. <2> Denosumab. <3> Calcitonin <4> Raloxifene. <5> Teriparatida.
