What Is One Reason Presidential Power Has Grown Since the Nineteenth

What is one reason presidential power has grown since the nineteenth century?

A) The presidency is characterized by unitary rather than collective decision-making processes.
B) Several constitutional amendments have granted additional expressed powers to the presidency.
C) The powers of the U.S. president were increased when the Senate consented to the United Nations charter in 1945.
D) Congress delegates increased power to the president in times of divided government.