Answer: For synergy with ground troops
Explanation:
Under Darius the Great, some Greek cities rebelled against the Persians with the support of Athens. Darius put down the revolt and wanted to punish Athens and sailed with a huge army and navy to do so.
The Persian fleet however sailed close to land instead of moving to invade Athens directly. This was said to be because the Persians did not want to risk sailing on the unfamiliar Aegean where they could suffer damage but instead wanted to share resources with the land army that was marching to Greece to mitigate this risk.
The progressive movement was mainly characterized by reform and a movement to reform an American society.
Hope this helps :)
The answer is A - underlying meaning.
