What gives you a good clue that chemical reactions are used to convert natural resources into synthetic products?

Question

the properties of synthetic materials and the natural resources used to make them are different.
synthetic materials and natural resources don't have any properties.
the properties of synthetic materials and the natural resources used to make them are the same.
it's impossible to compare and contrast the properties of synthetic and natural materials.

Answer 1

The best clue that chemical reactions are used to convert natural resources into synthetic products is:

the properties of synthetic materials and the natural resources used to make them are different.

This difference in properties indicates that a chemical transformation has occurred, altering the chemical structure and, consequently, the characteristics of the original natural materials to create synthetic ones.