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

Fluid viscosity directly impedes separation efficiency in both filters and centrifuges. Elevated temperatures reduce oil viscosity according to fluid dynamics principles, allowing suspended contaminants to migrate more freely through filter media or sediment out under centrifugal force.