Burton is using this list of rules for using commas to proofread his paper about mark twain. which sentence should he correct? a) mark twain was born in florida, missouri, in 1835. b) mark twain was the best known, and most successful author of his generation. c) mark twain worked as a steamboat pilot, a printer, a reporter, and an editor. d) although he was born samuel langhorne clemens, he used mark twain as his pen name.