Which sentence is punctuated correctly?
A. “Understand yourself, and you will understand everything, said Shunryu Suzuki. B. “Understand yourself, and you will understand everything,” said Shunryu Suzuki. C. Understand yourself, and you will understand everything, said Shunryu Suzuki. D. “Understand yourself, and you will understand everything, said Shunryu Suzuki.”