Which of the Following Statements Best Describes What Cofactors Are

Which of the following statements best describes what cofactors are?

A) They are metal ions that assist enzymes in carrying out their catalytic reactions.
B) They are organic molecules that assist enzymes in carrying out their catalytic reactions.
C) They are organic molecules called coenzymes.
D) They are organic molecules derived from compounds commonly known as vitamins.
E) all of the above