Which statement is correct?

the exponents in the rate law always match the coefficients in the balanced chemical reaction.
the exponents in the rate law must be determined by experiment.
the exponents in the rate law never match the coefficients in the balanced chemical reaction

The exponents in the rate law MUST be determined by experiment.

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

Order of the reaction is defined as the sum of the concentration of terms on which the rate of the reaction actually depends. It is the sum of the exponents of the molar concentration.

Order with respect to each reactant is determined experimentally and match the coefficients in the balanced chemical reaction for elementary reactions.

In equations, if the order with respect to each reactant is not equal to its stoichiometric coefficient which is represented in the balanced chemical reaction are complex reactions.