The correct answer is: C. Super chlorination.
Super chlorination is a process in which chlorine is added to water in excess of the amount required to achieve breakpoint chlorination. This is done to ensure that all of the organic matter in the water is oxidized and that the chlorine residual is high enough to protect against bacterial contamination.
Break point chlorination is the process of adding chlorine to water until the chlorine demand of the water is satisfied. This is the point at which the amount of chlorine added to the water no longer results in an increase in the chlorine residual.
Pre-chlorination is the process of adding chlorine to water before it enters a treatment plant. This is done to kill any bacteria that may be present in the water and to reduce the amount of organic matter that needs to be treated.
Post-chlorination is the process of adding chlorine to water after it has been treated. This is done to kill any bacteria that may have been introduced during the treatment process and to maintain a chlorine residual in the water.
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