Final answer:
A volcano best fits the definition of a landform made of layers of molten rock, as it is a geological structure formed by the eruption and solidification of lava.
Step-by-step explanation:
The word that best fits the definition of landforms made of layers of molten rock is Volcano. Volcanoes are geological formations created by the eruption of lava, ash, and gases from a magma chamber beneath the Earth's surface. When these materials reach the surface and cool, they solidify to form various types of volcanic landforms.
Volcanoes can create a wide range of features, including mountains, islands, plateaus, and plains. For example, if lava flows rapidly from long cracks, it can spread out to form lava plains, which are also composed of igneous rocks resulting from the cooling of molten rock.