Which of the following represents an ion?

• A. a particle having 9 protons, 9 neutrons, and 10 electrons
• B. a particle having 19 protons, 21 neutrons, and 19 electrons
• C. a particle having 14 protons, 14 neutrons, and 14 electrons
• D. a particle having 1 proton, 3 neutrons, and 1 electron