The correct answer is B) The vessel can steam on a constant heading (disregarding wind, current, etc.). The major advantage of a rhumb line track is that it allows the vessel to maintain a constant compass heading throughout the voyage, disregarding the effects of wind, current, or other external factors. This makes it easier for the navigator to plan and execute the voyage, as the vessel can simply follow a fixed compass bearing rather than constantly adjusting the course to account for changing conditions. The other options are incorrect because: A) a rhumb line does not approximate a great circle on east-west courses in high latitudes; C) the rhumb line is not necessarily the shortest distance between two points, as a great circle course would be shorter; and D) the rhumb line is not easily plotted on a gnomonic chart, which is more suitable for great circle courses.