Which Behavior Would Have the Least Impact on the Validity

Which behavior would have the least impact on the validity and reliability of a study using agency records?

A) discretion of prosecutors in who to charge and what counts to add
B) decisions that are made by police officers to arrest versus give a warning
C) recognition on the part of the researcher that criminal justice data is a composite of criminal behavior, ability to detect that behavior and decisions about system response to that behavior
D) decisions made by probation officers to revoke on new crimes and not technical violations