According to the adsorption theory of catalysis,the speed of the reaction increases because

• A
  Adsorption lowers the activation energy of the reaction
• B
  The concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption
• C
  In the process of adsorption,the activation energy of the molecules becomes large
• D
  Adsorption produces heat which increases the speed of the reaction