D. completing formal schooling.
The correct answer will be C!!!
The primary causes were that Sparta feared of the growing power and influence of the Athenian Empire. The Peloponnesian war began after the Persian Wars ended in 449 BCE. This disagreement led to friction and eventually outright war. Additionally, Athens and its ambitions caused increasing instability in Greece.
The billions that the United States spent eventually caused a recession. The initial plan was to win the war and utilize the resources from Vietnam along with several trade agreements to repay the expense that we made during the war. Since we lost and forced to retreat, the billions caused recessions that lead to more than 10% unemployment rate