The statement that correctly compares synthesis and decomposition reactions is:
Synthesis and decomposition reactions are opposites of each other. Synthesis reactions are in the form A + B → AB, while decomposition reactions are in the form AB → A + B.
In synthesis reactions, two or more reactants combine to form a single product, represented as A + B → AB. In decomposition reactions, a single compound breaks down into two or more products, represented as AB → A + B.