Final answer:
The best explanation for why each river has its own set of characteristics is that rivers interact with the ecosystems they pass through, affected by environmental factors such as precipitation patterns, vegetation, and soil characteristics.
Step-by-step explanation:
The statement that best explains why each river has its own set of characteristics is b.Rivers interact with the ecosystems through which they pass. Rivers have distinct characteristics because of the variety of ecosystems they traverse and the differing aspects of each of those ecosystems. From the precipitation patterns to land use, vegetation, topography, and soil characteristics, all these environmental factors contribute to the unique nature of each river. The flowing water from rain and melted snow enters river channels and interacts dynamically with the surroundings. This includes gravitational pull directing the water downhill, as well as erosion and dissolution processes that contribute to distinctive river profiles. Additionally, the physical characteristics of the river, such as channel width, temperature, and speed of flow, evolve from the source to the mouth, further resulting in a unique set of conditions and ecosystems around each river.