The correct answer is C) Gravity tank overflow lines are lead directly to the lube oil sump. This is correct because in a gravity type lube oil system, the gravity tank is designed to overflow directly into the lube oil sump in order to maintain a constant oil level and prevent any potential leaks or spills from the system. The overflow line provides a safe path for excess oil to return to the sump, rather than having it flow elsewhere or potentially cause damage. The other answer choices are incorrect. A) is incorrect because gravity tanks do not typically have overflow alarms. B) is incorrect because a lube oil pump failure would not immediately damage turbine bearings, as the gravity tank would continue to provide oil to the system. D) is incorrect because the discharge from the gravity tanks flows to the lube oil pump suction, not directly to the pump.