84J4 A
 In FM communications, the information is applied to the carrier by:
A. Varying the frequency of the carrier to convey the information to other stations.
B. Varying the amplitude or the frequency of the carrier, depending on Double or Single-Sideband operations.
C. Varying only the frequency of the carrier, depending on Double or Single-Sideband operations.
D. Varying the amplitude of the carrier and keeping the frequencies in the sidebands constant.
