Presidential power has grown due primarily to the fact that their powers outlined in article 2 of the u. s. constitution are:
a. specific and clear
c. vast
b. not open to interpretation
d. broad and vague

The correct answer is d) broad and vague.

Presidential power has grown primarily due to the fact that their powers outlined in Article 2 of the U.S. Constitution are broad and vague.

The United States Constitution states the powers of the President but in general definitions. This ambiguity has allowed the presidential power to grow during the past years. Among the powers that the Constitution states are that the United States President in the Commander in Chief, is the Chief Executive of the nation, and the Chief Diplomat. But the President also has many informal powers such as issuing executive orders or negotiating executive agreements.    

classical republicanism, also known as civic humanism, is a form of republicanism  developed in the renaissance inspired by the governmental forms and writings of  classical  antiquity, especially such  classical  writers as aristotle, polybius, and cicero.

the secretary of state, appointed by the president with the advice and consent of the senate, is the president's chief foreign affairs adviser. the secretary carries out the president's foreign policies through the state department and the foreign service of the united states.