Answer:
A. Rift zone - site of seafloor spreading
B. Abyssal plain - Very flat part of the ocean floor
C. Ocean Trench - Underwater volcano
D. Seamount - Near the continental margin
Explanation:
All you choices are matched with their characteristics,
The rift zone is the site of seafloor spreading. This zone is the area or boundary where land masses or tectonic plates are spreading apart. This movement results in the formation of new crust.
The abyssal plain is the flattest part of the ocean floor and it is found in the deepest parts of the oceans. They happen to be the least explored part of the ocean.
Ocean trenches are sites of convergent boundaries. These are boundaries where tectonic plates move towards each other. Sometimes when they converge, it causes the denser plate to dive under the other plate or slip under. This movements create volcanoes.
Seamounts are underwater mountains that used to be underwater volcanoes. They can come in different sizes and shaped. Like if they are smaller mountains they're called sea knolls and if they have flat tops, they are called guyots.
