You can study reaction rates to answer which of the following questions? will the reaction go to completion? will the reaction occur? how can the reaction be slowed down? how many grams of product will be made?

You can study reaction rates to answer  : How can the reaction be slowed down

when we're talking about 'rates', we're talking about the speed of the reaction, which measure the amount of times the reactant needed to produce the desired effect

hope this helps