Doppler Radar Works on the Principle That, as Precipitation Moves

Multiple Choice

Doppler radar works on the principle that, as precipitation moves toward or away from the antenna, the ____.

A) light beam will measure the wind speed of tornadoes
B) light beam will measure the change in frequency of falling precipitation
C) returning radar pulse will change color compared to the transmitted frequency
D) returning radar pulse will change frequency compared to the transmitted frequency
E) returning radar pulse will be the same frequency as the transmitted frequency