In the Context of Quality of Data Obtained from Secondary

In the context of quality of data obtained from secondary research, the term "expertise" relates to:

A) how well the research can be altered or revised.
B) how current and representative the research data is.
C) the skill and background of the researchers.
D) how free the research data is from researcher biases.
E) the extent to which the research data can be applied to specific business problems.