When Marshall McLuhan Said That "The Medium Is the Message

When Marshall McLuhan said that "the medium is the message," what did he mean?

A) Changes in technology allow us to deliver a much wider variety of cultural content than ever before.
B) The medium through which we deliver our cultural content has the greatest power to change our cultural framework.
C) Television allows for a much more nuanced message to be delivered.
D) The Internet allows individuals to contact others much more easily than they could in the past.
E) Digital technology allows people to manipulate the mass media and create their own content.