Question

Which are called the flattest and smoothest regions of the oceans?
A. Continental shelf
B. Continental slope
C. Deep-sea plain/ Abyssal plains
D. Oceanic deeps or trenches

Answer 1

Hint: The water bodies cover almost three-fourths of Earth’s surface. These water bodies include oceans, seas, rivers, lakes, and lagoons. This realm of water bodies on Earth is often referred to as Hydrosphere.

Complete answer:
The oceans cover a vast majority of the Earth’s surface. The regions of the ocean beds can be classified as the continental shelf, continental slope, Abyssal plain, abyssal hill, seamount, ocean trench and ocean bed.
Continental shelf: This is the first region of the ocean bed from the surface of the ocean. This region extends no further than a few hundred feet. This is a relatively shallow area of the ocean bed and surrounds the land. The Continental slope is a submarine topographical component that associates the mainland rack to the deep plain, starting at a profundity of around 460 feet (140 meters).

Deep-sea plain abyssal plain: This is the region that extends from about 10,000 feet and covers a vast majority of the ocean bed. This region extends downwards from the continental slope. These contain relief features like hills, valleys, and seamounts. These underwater hills are biodiversity hotspots and are home to several thousands of known and unknown species. These are the smoothest and flattest regions of the ocean.

Oceanic trenches or deeps: This region extends several miles below the abyssal plain. These are a few of the deepest points on Earth.

Thus, option (C) is correct.

Note:The Mariana Trench is the lowest region on the Earth's surface. It is oceanic deep and is located at a depth of almost 11,000 meters. Being a part of the Pacific Ocean, its deepest point is known as the Challenger Deep.