What components are included in an "underground tank system"?

An "underground tank system" comprises several components that work together to ensure the safe and effective storage of hazardous materials such as fuel. The system typically includes the underground storage tank itself, which is the main component designed to contain the stored substance.

Additionally, the system features piping that connects the tank to dispensing or monitoring systems. This piping is crucial for transporting the liquid from the tank to points of use or measurement without leakage.

Moreover, ancillary equipment, which encompasses a variety of accessories and systems such as pumps, leak detection systems, and valves, is essential for the operation, safety, and regulatory compliance of the tank system. Each component plays a significant role in maintaining the integrity of the tank system and preventing environmental contamination.

Overall, a complete underground tank system is formed by integrating the underground storage tank, the necessary piping, and ancillary equipment, which together ensure proper functioning and compliance with safety regulations. This comprehensive inclusion makes it clear why the choice stating "All of the above" is the correct answer.