B) False.
If a proposed mechanism is consistent with the experimentally determined rate law, it does not necessarily mean that the mechanism is correct. The rate law only describes the relationship between the rate of a reaction and the concentrations of the reactants. While a proposed mechanism that is consistent with the rate law can provide a plausible explanation for how the reaction occurs, it is not definitive proof that the mechanism is correct.
A proposed mechanism must also be consistent with other experimental observations, such as the effect of temperature, pressure, and catalysts on the reaction rate, in order to be considered a valid explanation for how the reaction occurs. In addition, the proposed mechanism should be able to account for the experimental kinetic data obtained under a wide range of conditions.