When Should an Ethical Journalist Reveal the Identity of Her

When should an ethical journalist reveal the identity of her or his confidential source, according to Michael Dorsher's argument?

A) When a judge holds him or her in contempt of court
B) When he or she has served at least 85 days in jail, as did Judith Miller of The New York Times
C) Never (unless it could perhaps save someone's life)
D) When it's the only way for a grand jury to complete its work