Please help with this if you want a free 100 points yk

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.

Insert comma today we went to the store to the post office and to the park

Which statement most strongly develops a positive tone? a. i was happy when i received my first paycheck for my hand work. b. winter break is approaching quickly, and i cannot wait to go shopping for gifts. c. going to the beach is one of my favorite activities; i love surfing and paddle boarding. d. a sense of accomplishment overwhelmed me as i stepped into into the stage that sunny, glorious day of graduation.