Which of the Following Constitutes Four Types of Social Commerce

Which of the following constitutes four types of social commerce?

A) social networking sites, message boards, forums, and wikis
B) microsharing sites, media sharing sites, and social bookmarking and news sites
C) social games and gaming sites, socially enabled console games, alternate reality games, and virtual worlds
D) reviews and ratings, deal sites and deal aggregators, social shopping markets, and social storefronts
E) the Internet, social software, devices, and social media users