What Was the Turning Point That Gave Rise to the Modern

What was the turning point that gave rise to the modern institutional presidency?

A) the social strife arising from the civil rights movement
B) the economic and social turmoil of the Great Depression
C) the demands of managing a modern army during World War I
D) the rise and importance of television as a mechanism that brought the president into the living rooms of American citizens
E) the rapid contraction of government following the conclusion of World War II