Task: Text Categorization
Input (English): 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:  <0> K2Cr2O7. <1> Fe2 (SO4) 3. <2> K2CrO4. <3> KSCN <4> FeSO4.
Output (English): chemistry