043C D
 Which of the following statements concerning COSPAS-SARSAT is true?
a) EPIRBs are units that are used as alerting devices.
b) These are satellites in a low-earth polar orbit that detect EPIRB beacons on 406 MHz and relay the information to a Local User Terminal (LUT).
c) The Doppler frequency measurement concept is used to determine the EPIRB's location.
d) All of the above.
