The correct answer is B) 203°F to less than 212°F. This temperature range is typically required for the contaminated fuel oil fed to a centrifuge, as it helps maintain the proper viscosity for effective separation of contaminants. Fuel oils need to be heated to a specific temperature, usually between 203°F and just below the boiling point of 212°F, to reduce their viscosity and enable the centrifuge to efficiently remove water, sludge, and other impurities. The other options are incorrect because: A) 160°F to 180°F may be too low to achieve the necessary viscosity reduction, C) greater than 212°F could cause the fuel to vaporize, and D) selecting the temperature based solely on the viscosity index, without considering the centrifuge's operational requirements, would not be the most appropriate approach.