Teacher:Given a scientific passage and an answer, generate a question for the given answer.
Teacher: Now, understand the problem? Solve this instance: Passage: chlorine is added to an aqueous solution of bromide. iodine crystals are added to a solution of potassium bromide. Bromide is present in naturally occurring salt solutions called brines. Based on your answers, propose an effective method to remove bromide from brine. Answer: salt
Student:
Bromide is present in brines, which are naturally occurring solutions of what?