Which of the following is the last step when evaluating writing with a general rubric?

What is the central idea in this advice from branch rickey to jackie robinson?  

Before ending this lesson, take a moment to review an informative research essay you have written. you’ve probably already written a conclusion to the essay. but is it the best conclusion it can be? does it properly summarize the main subtopics of your essay? does it state in one or two sentences the “so what” of your topic. if your topic was abraham lincoln, your essay shouldn’t be just about abraham lincoln. it should answer, “so what about abraham lincoln? ” take five or ten minutes, and looking only at that single paragraph, revise your conclusion

The rich natural resources made the sacramento valley a "garden of eden." permanent villages were established about 8,000 years ago. which choice combines these two sentences from paragraph two to achieve a coherent flow of ideas? a) the rich natural resources made the sacramento valley a "garden of eden" and permanent villages were established about 8,000 years ago. b) permanent villages were established about 8,000 years ago and the rich natural resources made the sacramento valley a "garden of eden." c) the rich natural resources made the sacramento valley a "garden of eden; " and so the permanent villages were established about 8,000 years ago. d) because of the rich natural resources which made the sacramento valley a ‘garden of eden,’ native americans established permanent villages there 8,000 years ago.