Which of the Following Is Not True About Nucleophilic Catalysis

Which of the following is not true about nucleophilic catalysis?

A) Nucleophilic catalysts form new covalent bonds with the reactants.
B) Nucleophilic catalysis will not involve positively charged intermediates.
C) Nucleophilic catalysis is also called covalent catalysis.
D) A nucleophilic catalyst increases the reaction rate by completely changing the mechanism of the reaction.
E) Nucleophilic catalysts are often good leaving groups.