Which statement best describes how a boiler functions in a steam system?

The correct choice accurately captures the primary function of a boiler within a steam system. A boiler's main purpose is to convert water into steam through the application of heat. This steam can then be utilized to drive turbines, which are essential in various power generation processes. The boiler achieves this by heating water to its boiling point, allowing it to turn into steam that can be delivered to the turbines to do work.

When considering the other options, it's important to note that while water storage tanks do exist in steam systems, the boiler isn't primarily intended for this purpose. Instead, it actively converts water to steam for operational uses. Additionally, while boilers do need to maintain certain temperature and pressure levels for efficient operation, their primary role isn't to regulate these factors but rather to generate steam. Lastly, a boiler is not designed to serve as a filtration unit; its main function revolves around heat transfer and steam generation, not purification of the water. This understanding of the boiler's role is fundamental to effectively managing a steam system.