If Subpoenaed to Appear in Federal Court, or Before a Federal

If subpoenaed to appear in federal court, or before a federal grand jury, the president has the following lawful choices, except

A) assert "executive privilege" and refuse to appear regardless of court rulings.
B) appear, but assert the Fifth Amendment privilege against self-incrimination.
C) appear and answer questions, but answer in a self-serving way so long as technically truthful.
D) challenge the subpoena and refuse to appear until the issue is resolved by an appellate court.