In geographical context, a “Peneplain” is:

Answer: [A] a low-relief non-constructional plain formed through fluvial erosion

Peneplains are formed by wearing down of land due to weathering and erosion. A peneplain is a featureless plain formed due to fluvial erosion. Some occasional raised areas which survive due to high resistance to erosion are called monad nocks found in peneplains. 

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