What Are Possible Risks and Limitations to Ethnographic Research

What are possible risks and limitations to ethnographic research?

A) Universities can withdraw support for the researcher on ethical grounds if the research is carried out without the knowledge of the criminal or deviant group.
B) Researchers might be in a position where they witness crimes, or even participate in them.
C) Researchers might suffer serious punishment if they try to protect their sources' confidentiality from the government.
D) Ethnographic research is often criticized as being unscientific or subjective.
E) All of the above