The correct answer is D: Run first centrifuge as a purifier in series with second as clarifier and reduce throughput and increase 'shoot' cycles'. Explanation: To minimize the effect of water in the fuel, the best approach is to run the two centrifuges in series, with the first one acting as a purifier to remove the bulk of the water, and the second one functioning as a clarifier to further refine the fuel. By reducing the throughput and increasing the 'shoot' cycles (the process of discharging accumulated water and contaminants), the centrifuges can more effectively separate the water from the fuel, ensuring that only clean fuel is delivered to the engine(s). The other options, while potentially helpful, are not as effective as running the centrifuges in series with the purifier-clarifier configuration and adjusting the operating parameters accordingly.