Which route type crosses every meridian at a different angle?

The option identifying the route type that crosses every meridian at a different angle is the rhumb line. A rhumb line is a path on the surface of the Earth that crosses all meridians at the same angle. This characteristic makes the rhumb line ideal for navigation because it represents a constant compass direction. However, this means it does not take the shortest path between two points on the globe.

In contrast, a great circle route is notable for being the shortest distance between two points on the surface of a sphere. It intersects various meridians at different angles as it follows the curvature of the Earth, but this is not aligned with the definition of a rhumb line. A direct route is often used synonymously with a great circle route in aviation, primarily referring to the most efficient path between locations, again crossing meridians at changing angles. Lastly, a flight corridor is more about designated air routes for traffic management rather than a specific type of path defined by the angle at which it crosses meridians.

Thus, the rhumb line is distinguished by its characteristic of crossing meridians uniformly, contrasting sharply with other route types that have different intersecting angles.