Hand-held GPS units in modern phones identify your location by
(A) transmitting their location and time to GPS satellites.
(B) receiving location data of GPS satellites.
(C) receiving time data from GPS satellites.
(D) exchanging location and time data with GPS satellites.
I think correct answer is (D), but the key says correct answer is (C).
How can GPS work without knowing the location Suppose you don't know the location, how do you know where to send the data to and where to get the data from?