Answer : The correct option is, (A) by increasing the temperature of the reactants
Explanation :
Rate of a reaction : It is defined as the speed at which the reactants are converted into the products.
Rate of a reaction can be increases by many ways :
(1) By increasing the temperature of the reactants
(2) By increasing the concentration of reactants
(3) By increasing the surface area of the reactants
(4) By adding the catalyst in the reaction
(5) By increasing the pressure of the reacting gases
Hence, the rate of reaction can be increased by by increasing the temperature of the reactants.