Answer:
(4) Therefore, fishing is the major industry.
Explanation:
You would need to have a transition before this sentence; you cannot just include it at random, because you did not mention fishing anywhere in the entire paragraph.
Answer: D
Explanation:
The main idea is... well, the main idea. its supposed to be the theme of the story, or what you should take away from it.
I would say D, you definitely wouldn't want anything negative. Hope I helped! Sorry if I didn't. :)<span />