Question 83Motor Plants - QMED

The correct answer is B) 4. The main lube oil cooler is typically represented as item 4 in the illustrated main engine cooling water systems diagram. This is because the main lube oil cooler is responsible for cooling the engine's lubricating oil, which is a critical function to ensure proper lubrication and prevent engine damage. The other options, A) 3, C) 5, and D) 6, may represent other heat exchangers in the cooling system, such as the jacket water cooler or the charge air cooler, but they do not specifically depict the main lube oil cooler as indicated in the question.