Answer: No it is a set.
Explanation: (Though Each number is an element of the set )
C. They were careful to stay off Native American lands.
Native Americans did not have the same concept of land and property ownerships as the colonists. That made the conflicts increasingly difficult as settlers encroached on Native American lands.
<span>Athens was/is part of Greece, which is made up of thousands of islands in/around the Mediterranean sea, so it would have been particularly useful for ancient Athens, and really Greece as a whole, to have a powerful navy. They might be able to take just about any coastal land they pleased from their neighbors if Athens' navy is more powerful.</span>