Which Aspect of Social Media Sites Makes the Medium Most

Which aspect of social media sites makes the medium most appealing to niche marketers?

A) They help marketers target the best undifferentiated market segment.
B) They are used by a majority of Internet users in Canada, the United States and overseas.
C) They guide organizations on how to set up social media networks.
D) They cater to the needs of small communities of like-minded people.
E) They allow marketers to control the conversations on the network.