Sentence patterns will help you understand by using subject, verbs, and improving the way that you write and analyzing the sentence to be better.
Answer:
The answer is postage.
A postage has to do with shipping payment. A buisness letter doesn't need that but it does need a return address, date, their address.
Where the story takes place
A. The author enjoys the sights and sounds of the swamp. The descriptions gives this one away.
There is no indication that the author lives here, nor is there any mention of tourists. That takes out B and D. And while there is many sentences describing the birds, there is just as much description about other species, so we do not know C to be true. A is the best choice.
