The correct answer is B) check for gland leakage and any fire hazard. When pumping flammable liquids with a centrifugal pump, it is crucial to inspect the pump and surrounding area for any potential fire hazards before starting the pump. Checking for gland leakage is important, as any leakage could create a fire risk. Additionally, ensuring there are no other fire hazards in the immediate vicinity is necessary to prevent accidents and ensure safe operation. The other options, while potentially relevant in other scenarios, are not the primary considerations when preparing to pump flammable liquids. Priming the pump (option A) and checking the relief valve (option D) are important maintenance tasks, but they do not directly address the fire risk. Having a standby pump (option C) may be a good practice, but it does not directly mitigate the fire hazard.