Which One of These Most Closely Matches David Gordon's Definition

Which one of these most closely matches David Gordon's definition of a confidential source?

A) Someone who gives a journalist information off-the-record in exchange for a promise the journalist will safeguard his or her identity.
B) Someone who gives a journalist information off-the-record but gets no guarantee that the journalist will safeguard his or her identity
C) Someone who gives a journalist information for background use only
D) Someone who gives a journalist an anonymous tip