What Are the Two Factors That Make It Difficult to Measure

What are the two factors that make it difficult to measure the extent of white-collar crime?

A) Victims don't report it and the concept of white-collar crime is ambiguous.
B) Victims don't report it and the government definition of white-collar crime varies too much from the research definition.
C) The concept of white-collar crime is too ambiguous and the government definition of white-collar crime varies too much from the research definition.
D) The government definition of white-collar crime varies too much from the research definition and there is disagreement about how to go about measuring the extent of white-collar crime.