Which of the following sentences is punctuated correctly?

A. The deepest, place in the ocean is about 7, miles down the Mariana trench in the Pacific Ocean.

B. The deepest place in the ocean is about 7 miles down the Mariana trench in the Pacific Ocean.

C. The deepest, place in the ocean, is about 7, miles down the Mariana trench in the Pacific Ocean.

D. The deepest place in the ocean, is about 7, miles down the Mariana trench, in the Pacific Ocean.