The "Echo Chamber Effect" Is

The "echo chamber effect" is

A) the ability to present one's ideas to a global audience and invite a dialogue.
B) the practice of reading multiple blogs on a daily basis.
C) fragmenting an audience into small groups or niches that mass media use as a basis to develop specific content.
D) the practice of insulating oneself from dissenting viewpoints to such an extent that you are no longer able to understand or accept the beliefs or opinions of those with whom you disagree.