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: Most Gram-positive bacteria do not grow in MacConkey's medium because it contains: 
 Options:  <1> Bile salts and crystal violet. <2> Lactose and casein hydrolyzate. <3> Neutral red <4> Mannitol <5> Basic fuchsin
