Asedimentary is most likely found in all of the following except
riverbed
sea floor
volcanic mountain
lake bottom

volcanic mountain

Explanation:

The sedimentary rocks, or just the sediments, can be found in numerous places around the world. Most commonly they are found at places where the erosive processes are strong and where they can be deposited. Such places are the riverbeds, seafloors, and lake bottoms.

The sediments basically form by the small particles that have been removed from the igneous or metamorphic rocks through he erosion and weathering processes. We can comfortably say that the sediments are a product of the destruction of the other two types of rocks.

One place where the sediments can't be found are the volcanic mountains. The reason for this is that the volcanic mountains are made out of igneous rocks, but they also have new layers of igneous rocks formed because of the lava flows down their slopes.

C. Volcanic mountain

Explanation:

Sedimentation is found from Igneous base rocks it is transported by the running water, wind and so on. They transported and subsided through weathering and denudated the topographies. Running water eroded and settled the weathering materials in riverbed, lakes, dams, and sea floor. Volcanic mountains erupted and lavas are extruded outside and become solidified it is called as igneous rocks. Magma is source of Igneous rocks and it transformed to Sedimentary rocks and metamorphic rocks due to weathering and pressure, respectively.