A refuse collection system consisting of two chutes is to be provided in a 20 storied residential building with 2 flats/floor (average family size = 5) and with each chute serving one flat on each floor. Average quantity of refuse and its density are 880 g/person/ day and 240 kg/m3 respectively. If the cleaning interval is two days, then the minimum size of the refuse container (litre) at the bottom of each chute is _______________

• A. 730 to 740
• B. 630 to 640
• C. 530 to 540
• D. 430 to 440