What contains the main idea in a paragraph

Which techniques best describe the tone the author is using in this passage?

Collections grade 10 guiding questions collection 6 "letter from birmingham jail" by martin luther king jr lines 66-101 why might king have taken the time so early in the letter to delve into such minute details about steps taken and recent event in birmingham?

Which of the following is a complex sentence? a. after henry submitted his essay, he realized that he hadn't proofread the last page. b. identity theft is a growing problem, especially among seniors. c. we didn't have enough potatoes for dinner, so we served rice instead. d. jim tried to watch a video on a device connected to a crowded wireless network; as a result, the video stuttered and froze.