During primary sedimentation and biological treatment of waste water, vast quantities of sludge are generated which are
This outcome reflects quantitative reasoning, where ratio, percentage and series logic determine correct calculation. Option A captures this correctly because it meets mathematical and logical criteria, consistent with textbook descriptions and experimental observations in aptitude and reasoning.
Ref: Wren and Martin, High School English Grammar and Composition, Revised Edition, Chapter 12, discusses vocabulary and comprehension providing guidance for verbal aptitude and logical inference assessment.
