Which of the following is true regarding social media and other communication technologies in a ...

Which of the following is true regarding social media and other communication technologies in a social media environment?
A.    Companies should limit their online presence to prevent online attacks and malicious campaigns.
B.    Customers who feel they have been treated unfairly like these sites because they can use the public exposure as leverage.
C.    Companies should respond to each and every rumour or negative information that appears in social media.
D.    Customers that voice their negative opinions in a social media environment can easily be erased from the sites.