The shallowest part of the ocean floor, the gently sloping submerged edge of a continent, is the:

The continental shelf is the gently sloping, shallow part of the sea floor that extends from the coastline of a continent out to the point where the sea floor drops steeply. It is the shallowest part of the ocean.

Features of the continental shelf:

• Its average depth at the outer edge is about 100 to 200 metres.
• Its slope is very gentle, usually 1 degree or less.
• Its width varies greatly, from almost nothing along some mountainous coasts, such as the west coast of South America, to more than 1,000 km.
• The Siberian Shelf in the Arctic Ocean is the largest continental shelf in the world, extending up to about 1,500 km.

Why continental shelves are important:

Fishing: Shallow, sunlit waters rich in nutrients support huge numbers of fish. Most of the world's major fishing grounds, such as the Grand Banks and the Dogger Bank in the North Sea, lie on continental shelves.

Minerals and energy: Large deposits of petroleum and natural gas are found in shelf sediments. India's Mumbai High oil field lies on the continental shelf off Mumbai.

Divisions of the ocean floor (from the coast outward):

• Continental shelf: shallow and gently sloping.
• Continental slope: the steep slope beyond the shelf edge, going down to about 3,000 metres.
• Continental rise: a gentle slope at the foot of the continental slope, formed by sediments.
• Deep ocean basin: including abyssal plains (very flat areas, 3,000 to 6,000 metres deep), mid-ocean ridges and seamounts.
• Ocean trenches: the deepest parts of the ocean, formed where one plate sinks beneath another.

India's continental shelf:

The shelf is wider along the west coast, especially off Gujarat and Maharashtra, than along the east coast.

Why not the other options?

• ✗The continental slope is the steep part beyond the shelf.
• ✗The abyssal plain is the deep, flat ocean floor.
• ✗Ocean trenches are the deepest parts of the oceans.