Which sentence is punctuated correctly?

Question

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.

Answer 1

D: "Understand yourself, and you will understand everything," said Shunryu Suzuki.