How does the fourth paragraph help the author achieve his purpose?

For the Birds!

Dear Citizens of Triston,
As a concerned citizen of Triston and member of the North Carolina Conservation of Nature Council, I am asking for the community's help with a serious issue. First, I want to congratulate our town's mayor and city council for planning to build a new community theater. However, do they realize that building the theater on Asbury Woodlands will destroy the prime breeding ground for an endangered species?
The Bachman's warbler is a small bird about four inches in length. This green-backed bird has a bright yellow belly and face and is sometimes confused with the similarly colored hooded warbler.
Since 1897, the population of the Bachman's warbler has decreased from over 500,000 to fewer than 100 in North Carolina. The main reason is the destruction of the areas (like Asbury Woodlands) that it uses for its natural breeding grounds. Bachman's warblers prefer thickly wooded swamps and wet thickets in heavy, full-grown forests where they can build their nests and feed on insects.
This does not mean that we cannot build a community theater. A similar situation recently arose in Cape Pristo, North Carolina. Nobel Hotels canceled its plans to build a high-rise structure when it became known that the roseate tern, another endangered bird, was living in the suggested location. Nobel Hotels put up a new building several miles down the beach from the original location, and the roseate tern kept its habitat.
Our community has forever prided itself on caring for our natural surroundings. The city council has promised that the proposed theater will be "highly tasteful" and that the structure will "complement the spirit of our town."
The city council's honorable concern for the endangered Bachman's warbler would smooth the feathers of many voters. With their help and the support of our townspeople, future generations will appreciate the beauty of this little bird.

Sincerely,
Redmond Harris

A.) The author offers additional information to the readers by comparing the community theater to the Nobel Hotels.
B.) The author restates his claim that the building plan would destroy the breeding ground for the Bachman's warbler.
C.) The author suggests that a better solution would be to build a Nobel Hotel as did Cape Pristo, North Carolina.
D.) The author uses an example to point out how an alternative could satisfy both sides of the argument.