How does Facebook influence self$-$interest and the social interest?

Facebook serves

A$.$ the self$-$interest of its users, and the social interest of only its investors

B$.$ the self$-$interest of its users but not the social interest

C$.$ the social interest of advertisers because they can increase their revenue, but it does not serve the self$-$interest

D$.$ the self$-$interest of its investors, users, and advertisers as well as the social interest as people share information

E$.$ the self$-$interest of investors because they can make increased profits, but it does not serve the social interest