We can confirm that the information that best describes the author's central argument is that the internet has changed the lives, personality and behavior of young people today.
Explanation:
"It's complicated: The social lives of network teens" addresses with the internet has been influential in the life of the modern youth and how it has changed all the elements that make up their lives. We can see that the author uses as a main argument the fact that the internet is one of the most influential factors in the life of the modern youth, allowing his behaviors, relationships and activities to be managed by him.
The central argument of a text is that which presents the position of the author in relation to the subject that is being addressed.
