A few factors influence the rate of reaction, including :
Temperature. Most reactions increase in rate as temperature increases; most reactions slow down as temperature decreases.
Concentrations of the reactant. Raising the concentration of a substance will increase the speed of the reaction; lowering the concentration of a substance will decrease the speed of the reaction. The limiting reactant is the reactant that is completely used up in a reaction. When this is completely used up, the reaction will stop.
Catalysts. These are substances that speed up the rate of the reaction by lowering the activation energy. If a catalyst is added, the rate of reactions will increase. If a catalyst is removed, the rate of reactions will decrease. Enzymes are biological catalysts used in living things to speed up internal reactions.
Inhibitors. These are substances that slow down the rate of a reaction. If an inhibitor is added to a reaction, its rate will decrease. If an inhibitor is removed from a reaction, its rate will increase.
Thus, the right answer is B. Lowering the concentration of the reactants
