When the Obama Administration Refused to Comply with a Congressional

When the Obama administration refused to comply with a congressional subpoena for documents related to Operation Fast and Furious, a Justice Department program created to combat drug trafficking, it did so by citing executive privilege.In so doing, he was following the example of many past presidents, especially those serving after Richard Nixon, because:

A) presidents have hinted that their successors could pardon them for any crimes they may have committed while in office.
B) presidents have noted that the State of the Union gives them the power to more properly address congressional concerns, at least once a year.
C) the Supreme Court recognized, in a case involving Nixon's Watergate tapes, the validity of executive privilege.
D) the Supreme Court decided, during the Nixon era, that presidents had the absolute power to keep any other branches from demanding its communications records.