If two centrifuges are to be simultaneously used in series to treat residual fuel contaminated with both water and solids, how should the centrifuges be configured?

Correct Answer: Option B — The first centrifuge should be set up as a purifier and the second centrifuge should be set up as a clarifier.

Serial fuel treatment requires the first centrifuge to operate as a purifier to remove water and heavy sludge, followed by a clarifier to extract remaining fine solid particles.