The correct answer is A. Coagulation.
Coagulation is the process of adding chemicals to water to cause suspended particles to clump together and settle out. This is not always necessary in drinking water treatment, as many water treatment plants use other methods to remove suspended particles, such as filtration.
Sedimentation is the process of allowing suspended particles to settle out of water. This can be done naturally, or it can be accelerated by using a settling tank. Sedimentation is often used in conjunction with coagulation, as it
helps to remove the larger particles that have been coagulated.Softening is the process of removing minerals from water that can cause scale buildup in pipes and appliances. This is done by adding chemicals that react with the minerals and form a precipitate, which can then be filtered out.
Disinfection is the process of killing harmful bacteria in water. This is done by adding chemicals, such as chlorine or ozone, or by using ultraviolet light. Disinfection is essential to ensure that drinking water is safe to consume.