Whether using a centrifuge or a simple filter, oil cleaning and filtration will be the most effective when the oil is at a __________.

Correct Answer: Option B — high temperature and a low viscosity

Stokes' Law dictates that the settling velocity of particles in a fluid is inversely proportional to viscosity. Heating the oil reduces its viscosity, which significantly increases the rate at which water and solid contaminants can be separated from the oil, thereby maximizing the efficiency of both centrifugal and filtration systems.