Read the following statement. Changes must occur at a structural level in order to be considered chemical.

Which detail from the article provides the BEST example to support this statement?

A
For instance, a block of wood may feel rough when you run your finger across it but rubbing the wood with sandpaper smooths the surface so it no longer feels rough.
B
A piece of metal may be heated in a fire until it glows, but the metal is the same material before heating and after cooling.
C
Think about ice melting into water, and then water being heated up and turning into steam.
D
The creation of a new, solid substance from two liquid substances indicates that a reaction has taken place and altered the original substances.