Which of the Examples Below Would Create an Ethical Dilemma

Which of the examples below would create an ethical dilemma when doing applied research that is evaluative in nature?

A) In an attempt to measure the success of a prison pre-release program, the researchers measure re-arrests and re-convictions and determine those to be failures.
B) Program staff of a pre-trial diversion program visit the homes of those awaiting trial on a nightly basis to make sure that they adhere to a curfew.
C) Upon review of a juvenile probation department, researchers found that contact sheets, which are designed to keep track of both phone and personal interactions between the officer and the juvenile, in one probation officer's files were all dated June 15th.
D) To measure the success of an adult drug treatment facility, researchers offered both the clients and the treatment staff confidentiality.