Answer:
Abyssal Hill
Explanation:
The given words/phrases are directly related to the seafloor spreading process.
In the case of divergent plate motion, plates move in the opposite direction. Due to this, the thickness of the lithosphere decrease and with the increasing time, it results in the eruption of magma at the seafloor. In the ocean basin, these magmas erupt along the mid-oceanic ridge, and in the continental areas, it leads to the formation of a rift and later forms a rift valley.
Some of the segments of the mid-oceanic ridge in the oceans are quite gentle with no roughness along the slope and some segments are steep and rough. It occurs because of the differences in the spreading rate, and this is commonly known as oceanic rise. The rocks that are formed at the mid-oceanic ridge are the youngest of all other rocks.
The odd one here is the abyssal hill, which is formed generally at the seafloor. When the areas at the abyssal plains are comprised of large deposits of sediments forming a hill, then it is called an abyssal hill. It is not related to the seafloor spreading. It is simply a feature of the ocean floor.
