Final answer:
NAVSTAR GPS satellites are approximately 20,000 km above the WGS 84 ellipsoid. Option A) 20,200 km is the closest to this height. The satellites' orbit and precision are influenced by General Relativity.
Step-by-step explanation:
The NAVSTAR GPS satellites circle the Earth at an approximate height above the WGS 84 ellipsoid. Based on the provided information, the satellites are in orbits that are approximately 20,000 kilometers above Earth. This height falls into none of the given ranges a) 600 km, b) 6,000 km, c) 36,000 km, or d) 385,000 km, which correspond to low Earth orbit, roughly Earth radius, geosynchronous orbit, and the approximate distance to the moon, respectively. Furthermore, the impact of General Relativity at this altitude, which causes the clocks on the GPS satellites to tick approximately 45 millionths of a second faster than on Earth, is critical for ensuring the precision of the GPS system. If these relativistic effects were ignored, positions would be off by about 7 miles in a single day. Therefore, the satellites must maintain this precise altitude to provide accurate location data. Given the options, the correct answer is A) 20,200 km, which is closest to the actual height of 20,000 km above Earth mentioned in the reference information.