What role did Themistocles play during the Greco-Persian Wars?
He led the Athenian navy at the Battle of Salamis.
He recorded the story of the Greco-Persian Wars.
He led the Persian invasion of the island of Marathon.
He defended a mountain pass against the Persian army.
He wasn't a historian, he wasn't involved much in the Battle of Marathon, and he did not defend a mountain pass against the Persian army, so that leaves A.
