Alum is used as A. An analgesic B. A fertilizer C. A disinfectant D. A purifier for water

The correct answer is D. Alum is used as a purifier for water.

Alum is a naturally occurring mineral that is used in a variety of applications, including water purification. Alum is a type of salt that is effective at removing impurities from water, such as bacteria, viruses, and parasites. It is also used to remove sediment and other particles from water. Alum is a safe and effective way to purify water, and it is used in many different

Option A is incorrect because alum is not an analgesic. Analgesics are drugs that relieve pain. Alum is not a drug, and it does not have any pain-relieving properties.

Option B is incorrect because alum is not a fertilizer. Fertilizers are substances that are added to soil to improve plant growth. Alum is not a fertilizer, and it does not have any properties that would improve plant growth.

Option C is incorrect because alum is not a disinfectant. Disinfectants are substances that kill or inactivate harmful microorganisms. Alum is not a disinfectant, and it does not have any properties that would kill or inactivate harmful microorganisms.