After a woman was injured in a workplace accident, she applied for federal disability benefits and was examined by a doctor employed full-time by the SSA to make recommendations to the agency about benefit eligibility. After the SSA denied the woman's application for benefits based on the doctor's initial examination, the woman filed numerous administrative appeals with the agency and lost. Later, after the woman discovered that a staff member at the SSA appointed the doctor to her position, the woman filed a federal lawsuit alleging that the doctor's appointment had violated the Article II appointment's clause. A reviewing court is most likely to rule that the doctor's appointment is:
a) Unconstitutional, as it violates the separation of powers
b) Constitutional, as the doctor's role is administrative and not a principal officer
c) Unconstitutional, as it infringes on the woman's right to due process
d) Constitutional, as the SSA has the authority to appoint its own staff