Interpret what a higher kinematic viscosity usually indicates about a lubricating oil’s volatility and safety limits—particularly its flash and fire points.

Introduction:
Viscosity correlates with molecular weight distribution and volatility in lube oils. Heavier, more viscous oils generally exhibit higher flash/fire points because fewer light, volatile components are present.

Given Data / Assumptions:

• Property under consideration: viscosity of a lubricating oil.
• We relate it to flash point and fire point behavior.

Concept / Approach:
Flash/fire points reflect the temperature at which sufficient vapours form to ignite/sustain combustion. Lower volatility (heavier/viscous oils) requires higher temperatures to produce ignitable vapour concentrations.

Step-by-Step Solution:

Verification / Alternative check:
Empirical data across lube grades show flash point trending upward with viscosity index/grade, barring additive anomalies.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming any property increase implies higher reactivity/acidity; viscosity is not a direct measure of acidity.

Final Answer:
Higher flash point and higher fire point