What is the maximum distance along the Earth's surface that is normally covered in one hop using the E region?

The E region is located in the middle of the ionosphere, roughly 90 to 120 kilometers above the Earth's surface. Because it is much lower than the F layers, a radio wave refracted by the E region returns to Earth at a steeper angle, covering less horizontal distance. The maximum possible distance a signal can travel in a single hop is dictated by the height of the refracting layer and the curvature of the Earth. For the E region's altitude, the geometric limit for a single hop is about 2,000 kilometers. To communicate further than 2,000 km using the E layer, the signal would need to undergo multiple hops between the Earth and the ionosphere. The 4,000 km option is incorrect because that represents the maximum single-hop distance of the higher F2 region.