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 forces that stabilize the alpha helix are: 
 Options:  <1> Intra-chain hydrogen bridges parallel to the axis of the helix. <2> Disulfide bridges between methionines. <3> Hydrogen bridges between chains perpendicular to the axis of the helix. <4> Van der Waals forces among the radicals. <5> Links between lysine radicals.
