The correct answer is A) Proposing a safe way to pass. According to the Inland Navigation Rules, when two power-driven vessels are meeting in a narrow channel, the vessel proceeding with the current (the downbound vessel) has the responsibility to propose a safe way to pass the upbound vessel. The upbound vessel must then promptly signal their intention to accept or reject the proposed passing arrangement. This is to ensure that the vessels coordinate their actions and safely pass each other in the narrow channel. The other options are incorrect because B) waiting for the other vessel to signal first is not the responsibility of the downbound vessel, C) backing down is not necessary if a safe passing arrangement can be proposed, and D) is not the correct answer as the downbound vessel has the specific responsibility to propose the safe passing.