The correct option is B b) i, iv, ii, iii
b)
Explanation: Ocean bottom topography is divided majorly into the continental shelf, the continental slope, Oceanic deeps and The deep sea plains.
Continental shelves are the shallowest part and extended margins of the continent.Continental slopes connect the shelves with oceanic basins. These structures sharply drop off into a steep slope.
Deep-sea plains are the flattest and smoothest regions on the earth. Depths vary between 3000-6000m. These are covered with fine-grained sediments like clay and silt.
Trenches are about 3-5 km deep. Occur along the island arcs, active volcanoes and strong earthquakes