The correct answer is B) Minimizes oil leakage from the rotor shaft. The main purpose of pressurizing the lube oil sumps on a marine gas turbine is to create a positive pressure within the bearing housing, which helps to prevent oil leakage from the rotor shaft. This positive pressure ensures that any potential leakage paths are sealed, reducing the risk of oil escaping the bearing housing and potentially causing operational issues or environmental contamination. The other answer choices are incorrect because: A) Uniform oil distribution is achieved through the design of the lubrication system, not specifically by pressurizing the sumps. C) Increased oil penetration is not the primary purpose of pressurizing the sumps. D) Cooling the oil is a separate function, typically handled by the oil cooler or heat exchanger, not the pressurization system.