Final answer:
The shallowest parts of the ocean along the margins of continents are the continental shelves, which are submerged parts of the continental crust in shallow water extending from the shoreline to the shelf break. The correct option is d.
Step-by-step explanation:
The shallowest portions of the ocean found along the margins of continents are known as the continental shelves.
These structures are the submerged portion of continent crust in relatively shallow water, extending from the shoreline to the drop-off point marked by the shelf break.
The continental shelf is part of the continental margin lying between the shoreline and the shelf margin and is generally less than 180 m (600 ft) in water depth.
Unlike the continental slope, continental rise, or abyssal plains, the continental shelf represents the submerged edges of the continental landmass, providing extensive areas for marine life, including environments where coral reefs may be found due to the shallowness of the water. The correct option is d.