Correct answer choice is:
C. GPS.
Step-by-step explanation:
The Global Positioning System (GPS) is a system of around 30 satellites revolving around the Earth at an elevation of 20,000 km. Once it has data on how far apart at slightest three satellites are, your GPS receiver can pinpoint your position applying a method termed trilateration.
GPS Mechanism:
Firstly, the signal of time is transmitted from a GPS satellite at a delivered position. Consequently, the time interval between GPS time and the point of time clock which GPS receiver acquires the time signal will be measured to produce the range from the receiver to the satellite. The equivalent method will be performed with three different possible satellites. It is likely to estimate the location of the GPS receiver from the length from the GPS receiver to three satellites.