Which of the following choices shows a correct use of hyphens and dashes?

A. Marguerite-never one to show caution-leapt into the blue—green water.
B. Last Sunday-look out! That's the shallow—end!
C. There is—one person-my sister-who can sort out the mixed-up papers.
D. Jones is a well-known poet—not that I like his work that much.