What action is required for a sailing vessel when it approaches a power-driven vessel?

The requirement for a sailing vessel when approaching a power-driven vessel is indeed that it must keep out of the way unless it has the right of way. In typical navigation scenarios, sailing vessels, which are considered to be under sail, generally have a responsibility to avoid collisions with power-driven vessels, particularly when the power-driven vessel is constrained by its ability to maneuver.

The Navigation Rules, often referred to as COLREGs (International Regulations for Preventing Collisions at Sea), establish these guidelines to promote safety on the waterways. Specifically, when a sailing vessel is on a collision course with a power-driven vessel that is not overtaking, the sailing vessel is usually in the 'stand-on' position because it is under sail. However, the sailing vessel must assess its right of way based on its sailing mode, and if the power-driven vessel is in restricted maneuverability or navigating a narrow channel, the sailing vessel must yield to avoid a collision.

This requirement helps prevent accidents by establishing clear responsibilities between different types of vessels. The other options do not accurately reflect the rules governing the interaction between these two types of vessels, as they either overstate the obligation of one vessel or suggest an erroneous scenario where one vessel has no obligations.