Which nordic country is entirely within the north european lowland landform ?

The country is Denmark.

Denmark is a Nordic country located further south among the Scandinavian countries. It consists of mainly of flat land topography while there are few elevated areas. The Jutland Peninsula is a hilly area which has the average height of 31 m above sea level while the highest point on the hill is 170.86 meters above sea level.  The lowest point in Denmark is 7 meters below sea level.

Due to lowly lands, the coast is vulnerable to flood and erosion requiring measures to protect the land against such disasters. These include installation and construction of flood controlling structures.

the correct answer is c