Answer:
The cause and effect relationship described in this section is the establishment of the communication revolution caused by the invention of printing press.
Step-by-step explanation:
Cause and effect relationships are those that present a situation where one element causes the creation and another element, that is, these elements have such a strong connection between them, that one becomes the result of the existence of the other.
Right at the beginning of the section entitled "The first communication revolution" we have an example of this type of relationship when the author states that the cause of the communication revolution was the creation of the printing press.