Which of the Following Statements About the Ethics of Internet

Which of the following statements about the ethics of internet research are true?

A) Online research that involves direct contact with participants are subject to the same ethical protocols as in-person research.
B) Because social media is public domain, there are no concerns about privacy or confidentiality that need to be considered.
C) Using real Twitter handles in a research study is never problematic.
D) Covert research when done online is not ethically problematic.