In regulatory terms, what does 'navigable waters' refer to?

Navigable waters specifically refer to bodies of water that can be used for interstate or foreign commerce. This definition is crucial because it aligns with legal standards set by various regulatory bodies, such as the U.S. Army Corps of Engineers and the Environmental Protection Agency, which govern waterway usage and environmental impacts. The ability of waters to support commercial activities, such as transporting goods and facilitating trade, is central to this classification. Since interstate and foreign commerce is a key aspect of economic activity, this definition helps in determining jurisdiction and regulatory authority over these waters.

The other options do not capture this specific legal and economic context. For instance, while any waterway open to public access could imply navigability, it does not necessarily mean those waters support commerce. Similarly, defining navigable waters as all waterways is overly broad and would not align with the specific regulatory frameworks that focus on economic use. Limiting the definition to only lakes and rivers excludes other significant waterways, such as bays and estuaries, that are also vital for commerce. Therefore, option B is the most accurate representation of what 'navigable waters' entails in regulatory terms.