Why are some military IR routes thicker than others as shown in the figure below? (See Figure 8.) Group of answer choices The thick IR routes are more heavily traveled by military aircraft The thin IR routes are 5 nautical miles (nm) or less from the center line to the edge of the route, the thick ones are wider than 5 nm from the center to the edge of the route The thin routes have fighter aircraft flying these routes, so they will be faster than other aircraft