$A$ catalyst is a substance which

Which statement is incorrect for a catalyst?

The number of correct statements about modern adsorption theory of heterogeneous catalysis from the following is ..........
$A.$ The catalyst is diffused over the surface of reactants.
$B.$ Reactants are adsorbed on the surface of the catalyst.
$C.$ Occurrence of chemical reaction on the catalyst's surface through formation of an intermediate.
$D.$ It is a combination of intermediate compound formation theory and the old adsorption theory.
$E.$ It explains the action of the catalyst as well as those of catalytic promoters and poisons.

Explain: How does a catalyst increase the rate of a reaction?

What is a catalyst?

$A$ catalyst remains unchanged at the end of the reaction regarding