Which of the Following Statements Is True

Which of the following statements is True?

A) The body of a trigger cannot read or modify the primary, unique, or foreign key columns of a constraining table.
B) The body of a trigger cannot read or modify the primary, unique, or foreign key columns of a key-preserved table.
C) The body of a trigger cannot read or modify the primary, unique, or foreign key columns of a mutating table.
D) The body of a trigger cannot read or modify the primary, unique, or foreign key columns of a conditional table.