Which statement best describes a chemical reaction?
A. In a chemical reaction, one or more substances called products are combined or broken down to form reactants.
B. In a chemical reaction, one or more substances called products are combined or broken down to form compounds.
C. In a chemical reaction, one or more substances called reactants are combined or broken down to form products.
D. In a chemical reaction, one or more substances called reactants are combined or broken down to form elements.