Which of the Following Statements Is False

Which of the following statements is false?

A) The atomic mass unit is exactly 1/12 of the mass of a carbon-12 atom
B) Both protons and neutrons have atomic masses very close to 1 u
C) A carbon-12 atom with six electrons has a mass of 12.6 u
D) The atomic mass of an element is the average mass of the atoms of an element compared to an atom of carbon-12 at exactly 12 u
E) To find the atomic mass of an element, you must know the atomic mass of each isotope and the fraction of each isotope in a sample