d.Continental Shelf
Step-by-step explanation:
See Article History
Continental shelf, a broad, relatively shallow submarine terrace of continental crust forming the edge of a continental landmass. The geology of continental shelves is often similar to that of the adjacent exposed portion of the continent, and most shelves have a gently rolling topography called ridge and swale. Continental shelves make up about 8 percent of the entire area covered by oceans.