Which of the Following Statements Does Not Describe the Standard

Which of the following statements does not describe the standard expected of experts?

A) Must exercise skill with degree of care expected from a reasonable person in that profession.
B) The standard of an expert need not be perfection.
C) Inexperience does not excuse incompetence.
D) Common practice always sets the appropriate standard.
E) Require skills and abilities expected of a professional in that field.