755. If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is_________________? September 7, 2025 by Admin A. 50 mg/l B. 100 mg/l C. 150 mg/l D. 250 mg/l ✅ The correct answer is option D.
