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 color centers or F centers are produced: 
 Options:  <1> Exclusively in crystals that contain fluorine. <2> By heating a crystal in the vapor of an alkali metal. <3> By cooling a crystal in the vapor of an alkali metal. <4> By heating a crystal in the presence of fluorine. <5> By cooling a crystal in the presence of fluorine.
