ANSWER
EXPLANATION;
Law of conservation of mass states that matter can neither be created nor destroyed but can be transformed from one form to another. During chemical reaction, only the atoms in the reactants can end up in the products
During reaction, the reactants contact each other, the bonds binding the atoms are broken and the atoms re-arrange to form a new bonds to make the products
Therefore, atoms re-arrange during chemical reaction
Hence, the correct answer is option A