Answer:
A.) The reaction rate decreased.
Step-by-step explanation:
Let's review the rate law based on the effect on concentration on reactions: typically, reaction rates decrease with time because reactant concentrations decrease as reactants are converted to products. Reaction rates generally increase when reactant concentrations are increased.
Based on this logic, the reaction rate when the concentration of reactants is decreased, this would have a decreased too. The answer would be A.) The reaction rate decreased.