Answers:
Number 2: Pine Trees.
Number 3: The Coastal Plain.
Explanation for number 2: The lower part of the Coastal Plain does not have very fertile soil, so not many things can grow except for pine trees and brush.
Explanation for number 3: None needed.
B WOULD BE THE ANSWER TO THIS QUSTION
Political if you are talking about where the country meet another and its a natural boundary if it is physical like a river or mountain range
