The correct answer is C) lube oil coolers. In a pressure type main propulsion turbine lubrication system, the lube oil service pumps typically take suction from the main sump and discharge directly to the lube oil coolers. This is to ensure the lube oil is properly cooled before it is distributed to the various bearings and other components that require lubrication. The lube oil coolers help maintain the proper temperature of the lubricating oil, which is crucial for the efficient and reliable operation of the turbine's lubrication system. The other options are incorrect because: A) the gravity feed tank is not the direct discharge location for the lube oil service pumps, B) the main thrust bearing is a component that receives the cooled lube oil, not the direct discharge point, and D) the lube oil header is the distribution point for the cooled lube oil, not the direct discharge location from the service pumps.