"many critics argue that has been damaging the quality of radio content by drowning out diverse voices."

Many critics argue that channel has been damaging the quality of radio content by drowning out diverse voices.

Channel in mass media is a band of frequencies that we used in television and radio transmission, especially by one particular radio or TV station.

In broadcasting history, the channel is the main component in broadcasting or transmitting information from a certain station to another, but in channel, it is also where all the noise took place.  Sometimes, when we listen to a certain radio station, if the radio frequency we often hear overlapping noises, and that is because of the channel. This is the reason why critics blamed the channel to have a damaging effect in broadcasting, especially in radio.

answer; (a) calling people who have not shown interest in the product and asking them to buy it;