What Is a Global Positioning System (GPS)

What is a global positioning system (GPS) ?

A) A constellation of 24 well-spaced satellites that orbit the Earth and make it possible for people with ground receivers to pinpoint their geographic location
B) Designed to work with information that can be shown on a map
C) Contains a microchip and an antenna, and typically work by transmitting a serial number via radio waves to an electronic reader, which confirms the identity of a person or object bearing the tag
D) Commonly used to transmit network signals over great distances