According to the passage, the distance between a radar set and an object can be determined by

A. the time it takes for a burst of radio waves to produce echoes when the waves bounce off the object 

B. the term “ranging” used for detection of the distance between an object and the radar set 

C. the time it takes for the radio waves to produce echoes and bounce off the object 

D. the time it takes for the echoes produced by the radio waves to return to the radar set