What used diesel engine crankcase lubricating oil analysis test result would indicate the oil's ability to neutralize harmful acidic byproducts?

Correct Answer: Option C — Total base number

Total Base Number (TBN) measures the alkaline reserve in lubricating oil, which neutralizes acidic combustion byproducts. Maintaining an adequate TBN is vital for preventing corrosive wear on engine components. If TBN drops too low, the oil can no longer protect the engine from acid-induced damage, necessitating an oil change.