With respect to a lubricating oil's viscosity and the bearing loading characteristics at the points of lubrication, what statement is true?

Correct Answer: Option C — The viscosity should be high enough to withstand the greatest anticipated torque load, but the viscosity should be low enough to minimize power losses.

Lubricating oil viscosity must be high enough to maintain a hydrodynamic film under peak torque loads to prevent metal-to-metal contact. Simultaneously, it must be low enough to minimize internal fluid friction, which reduces power losses and heat generation, optimizing the efficiency and longevity of the bearing and the machinery.