Answer:
The term that best describes what a plate is made of is 'lithosphere'.
Step-by-step explanation:
- The oceanic crust and the continental crust together make up the lithosphere.
- A plate can be both, a continental plate or an oceanic plate, which are both ultimately a part of the lithosphere.
- The lithosphere is a non-uniform layer that lies and floats above the asthenosphere (the uppermost layer of the mantle).
- The floating of the lithosphere is due to the non-uniformity of the layer, which is because the layer is divided in number of plates.