Two years ago, the President of the US nominated a candidate for Secretary of Education. Due to an ongoing political dispute, the Senate refused to hold a confirmation vote on the candidate's appointment. Last month, during the Senate's thanksgiving break, the Senate unanimously adopted a resolution on November 20 to convene a "pro forma" session on November 23. The 30-second long pro forma session occurred, the Senate immediately went into an intra-session recess, and then reconvened a week later on December 1. During that seven-day break, the president invoked the Recess Appointments Clause to formally appoint the candidate as Secretary of Education. If subject to a constitutional challenge, a reviewing court would likely conclude that the candidate's appointment is:
a) Constitutional, as the Senate's pro forma session does not prevent the President from making recess appointments
b) Unconstitutional, as the Senate's pro forma session constitutes a valid recess
c) Constitutional, as the President has the authority to make appointments during any break in Senate sessions
d) Unconstitutional, as the President can only make recess appointments during a recess of at least ten days