Which of the Following Statements Best Explains the Political Circumstances

Which of the following statements best explains the political circumstances of the Greek world in the early fourth century BC?

A) City-states continued to grow in strength due to their reduced interest in warfare.
B) Persia withdrew itself from Greek political and military affairs as it turned toward strengthening its domestic economy.
C) The drastic reduction in the population of Thebes made it a minor power.
D) Sparta remained the undisputed leader in the Greek world.
E) The reduced circumstances of Sparta and Athens allowed other city-states, like Corinth and Thebes, to compete with them on more equal terms.