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 chloride present in a solution can be determined volumetrically, by the Mohr method, using Ag (I) as a reagent. What indicator is used in this assessment ?: 
 Options:  <1> K2Cr2O7. <2> Fe2 (SO4) 3. <3> K2CrO4. <4> KSCN <5> FeSO4.
