The term "power-driven vessel" refers to any vessel __________.

Answer: B — with propelling machinery in use

The term "power-driven vessel" specifically refers to any vessel that has propelling machinery in use. This includes vessels that are powered by engines, whether they are operating at full speed or just maneuvering. In the context of the navigation rules, the distinction is significant because power-driven vessels have specific obligations and rights compared to sailing vessels or those that are not actively using their engine. A vessel with sails deployed is primarily considered a sailing vessel, even if it may also have auxiliary power. Drifting and anchored vessels do not actively use their propelling machinery, which means they don't fit the criteria for being classified as power-driven vessels under the navigation rules. Therefore, the appropriate choice emphasizes the use of machinery as the defining characteristic of a power-driven vessel.