A mixture of ethanol and water is fed to a distillation column with a feed rate of 1000 kg/hr. The mixture contains 40% ethanol by mass. The column has a total of 20 trays and operates at a pressure of 1 atm. The top product is pure ethanol, while the bottom product is pure water. The reflux ratio is 2.5, and the boil-up rate is 15000 kg/hr. The relative volatility of ethanol to water is 1.5. Assuming ideal behavior and constant molar overflow, what is the flow rate of the bottom product in kg/hr? A) 725 kg/hr B) 750 kg/hr C) 775 kg/hr D) 800 kg/hr