Final answer:
The true statement about the four spheres (biosphere, atmosphere, hydrosphere, and lithosphere) is that they are all interconnected, with the hydrosphere interacting with the other spheres through processes like the water cycle.
Step-by-step explanation:
The statement that is TRUE about the four spheres is that they are all interconnected. This means that a change in one sphere often influences the others. Specifically, the hydrosphere is not isolated; it interacts extensively with the biosphere, atmosphere, and lithosphere. Interactions such as the water cycle clearly illustrate these connections. Not only does the hydrosphere encompass all the water on Earth, including freshwater, saltwater, groundwater, and ice, but it also plays critical roles in supporting life, regulating climate, and serving human needs. Disturbances to the hydrosphere, like overuse and pollution, can therefore lead to significant effects on other spheres.