What best describes the orbital arrangement of GPS satellites?

The correct description of the orbital arrangement of GPS satellites is that they are in six orbital planes that are equally spaced and inclined about 55 degrees to the equator. This configuration ensures that at any given time, a GPS receiver on the Earth's surface can have access to signals from at least four satellites, which is necessary to determine an accurate position.

The choice of six orbital planes allows for comprehensive coverage of the Earth, as the satellites circle the globe in such a way that there is redundancy and availability of satellite signals from various angles. The inclination of approximately 55 degrees provides a good compromise between coverage of the northern and southern hemispheres, optimizing the ability to navigate and collect geolocation data for users worldwide.

Other arrangements, like being in two orbital planes or clustering in one plane, would limit the visibility and availability of signals for users, which would negatively affect the accuracy and reliability of GPS services. Similarly, orbiting in a single circular orbit would not provide the necessary spatial orientation required for effective triangulation of positions across diverse geographic locations.