Answer: D. continental margins near the mouths of rivers
Explanation:
Terrigenous sediments are those that are formed via processes on land as opposed to in water. They result mostly from the erosion of rocks and yet make up 20% of all ocean sediments.
Continental margins near the mouths of rivers contain the thickest deposits of this sediments as they are closest to land which is the source. It is made more convenient by the presence of rivers bringing the sediments to them when the rocks are eroded.
