Percentage of Bacterial Load Removed from Water by Plain Sedimentation

Plain sedimentation is a process of water treatment that removes suspended solids and some bacteria from water. It is estimated that plain sedimentation can remove about 75% of the bacterial load from water.

Here is the summary of the topic:

Percentage of bacterial load that can be removed from water by the process of plain sedimentation is about
a) 10 to 25
b) 50
c) 75
d) 100

Here is the original question:

Que 59. Percentage of bacterial load that can be removed from water by the process of plain sedimentation is about