Most offshore drilling occurs:

A. near trenches

B. in the middle of the ocean

C. on the continental shelf

D. in the United States

D.

If we look into the history, mostly offshore drilling began by extending known coastal oil - and gas-producing trends out into the ocean. For this reason, most US offshore drilling has taken place offshore Louisiana, Texas, California, and Alaska, areas with coastal onshore oil and gas fields.

A. near trenches