Which One of the Following Statements Is Not Correct

Which one of the following statements is not correct?

A) Oxygen-15 is unstable because it has too few neutrons.
B) Nucleons are held together in a nuclide by the electromagnetic force.
C) All nuclides with Z < 83 decay into more stable nuclides with smaller Z values.
D) As the atomic number increases, the ratio of neutrons to protons in a nuclide increases.
E) Generally, the number of neutrons in a nuclide equals the number of protons, or nearly so, when the atomic number is small, i.e., Z < 18.