Come on writing is fun try it yourself!
If you're asking for main idea, the main idea or thesis statement sentence is sentence 1, where they explain what the passage is about.
The sentence which uses correct punctuation is C. In time, of course, all issues get resolved, but not necessarily in the way you would like.
In A, the comma before <em>he was concerned </em>should be a dash. In B, there should be a colon before <em>a flashlight, </em>not a semi colon. In D, there should be a comma before <em>yet, </em>and not a colon.
