According to the Historian Thucydides,the Peloponnesian War Began

According to the historian Thucydides,the Peloponnesian War began:

A) as a way to permanently remove the Persian threat from the Aegean Sea.
B) because Sparta feared the growing power of Athens.
C) to facilitate the expansion of Athens into Syracuse (Sicily) .
D) because Athens failed to support the Delian League.
E) when Sparta's imperial ambitions threatened the Greeks north of the Peloponnesus.