Which of the following describes the process of steam generation in a boiler?

The process of steam generation in a boiler fundamentally involves heating water to the point of boiling, which produces steam. When water is heated, its molecules gain energy, leading to an increase in temperature until it reaches the boiling point. At this point, the water transitions from the liquid phase to the vapor phase, forming steam.

This steam is then used for various applications, including powering turbines, heating, or driving other mechanical processes. The efficiency of steam generation is significantly influenced by various factors such as temperature, pressure, and the type of fuel used in the boiler.

In summary, the correct answer correctly captures the essence of how steam is produced in a boiler through the direct application of heat to water, resulting in vaporization.