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: How is the pigmented and highly vascularized layer of the posterior wall of the eyeball called? 
 Options:  <1> Iris. <2> Choroid <3> Ciliary body. <4> Sclera <5> Retina.
