E4A01 (C) 
How does a spectrum analyzer differ from a conventional oscilloscope?
A. A spectrum analyzer measures ionospheric reflection; an oscilloscope displays electrical signals
B. A spectrum analyzer displays the peak amplitude of signals; an oscilloscope displays the average amplitude of signals
C. A spectrum analyzer displays signals in the frequency domain; an oscilloscope displays signals in the time domain
D. A spectrum analyzer displays radio frequencies; an oscilloscope displays audio frequencies
