Answer the following question given this paragraph: 

An example of a physical model is a drawing of the layers of Earth ( Figure below ). A drawing helps us to understand the structure of the planet. Yet there are many differences between a drawing and the real thing. The size of a model is much smaller, for example. A drawing also doesn’t give good idea of how substances move. Arrows showing the direction the material moves can help. A physical model is very useful but it can’t explain the real Earth perfectly.


Q: What was diorite commonly used for in ancient civilizations?

 Choices:

- school

- currency

- medicine

- art

A:
art
