In an FM Stereo Receiver, What Is the Purpose of the AM

Multiple Choice

In an FM stereo receiver, what is the purpose of the AM detector stage?

A) It mixes the L+R and L-R signals to produce separate L and R audio signals
B) It converts the L-R DSB signal back into an L-R signal at audio frequencies
C) It converts the L+R DSB signal back into an L+R signal at audio frequencies
D) It filters out the 19 kHz pilot carrier from the complex discriminator output signal