What should be done with unused fuel at the end of an operation?

Storing unused fuel in approved containers for future use is the best practice for managing leftover fuel at the end of an operation. This approach not only complies with environmental regulations but also promotes resource efficiency. Proper storage extends the lifespan of the fuel and reduces waste, allowing it to be used effectively in future operations instead of being disposed of prematurely.

Approved containers are specifically designed to handle fuel safely, minimizing the risk of spills or leaks that could harm the environment or pose safety hazards. Additionally, maintaining the integrity of the fuel through proper storage conditions preserves its quality, ensuring it remains usable.

The other choices involve methods that could be harmful or illegal. Discarding the fuel in landfills poses environmental risks, burning it may create air pollution, and allowing it to evaporate wastes valuable resources. Hence, storing unused fuel appropriately is a responsible and efficient choice.