The correct answer is C) They built up their navy into a fleet of about 200 boats.
What the Athenians did in preparation for Xerxes's invasion was that they built up their navy into a fleet of about 200 boats.
Xerxes was the son of Dario, King of Persia. After the death of his father, Xerxes led the Persian Army in the Second Persian Invasion of Greece with a huge army bever before seen. First, the Persians defeated the Spartans in the Battle of the Thermopylae. Then, advance into Athens to capture it. However, when they tried to eliminate the entire Athenian fleed they were defeated in the Battle of the Salamis. The Greeks finally defeated the Persians in the Battle of Plataea to end the bloody war.
