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.
The answer would be self-esteem.
I hope that helped :)
The answer would be A.
The description of "Unlike normal rocks, they have trails etched behind them as if they have traveled across the sand.", provides detail to support the main idea that "drifting" rocks are strange. Some keywords that will help you understand the main idea that "Drifting Rocks are Stange" :
°Unlike
°Traveled
°Trails