The correct answer is C) 247.5°. The compass course of a vessel heading WSW (West-Southwest) is 247.5°. This is because WSW is a primary intercardinal direction, which is the midpoint between a cardinal direction (N, E, S, W) and an adjacent ordinal direction (NW, NE, SE, SW). The compass bearing for an intercardinal direction is calculated by taking the average of the two nearest cardinal directions, which in this case are West (270°) and South (180°), resulting in 247.5°. The other answer choices are incorrect because A) 202.5° is too far to the south, B) 225.0° is the correct bearing for a vessel heading SW, and D) 271.0° is too far to the north of the WSW direction.