Given That an Unknown Atom's Mass Number (AMU) Is 27

Multiple Choice

Given that an unknown atom's mass number (AMU) is 27, its combination of particles could be

A) 27 electrons, 16 neutrons, 16 protons.
B) 27 neutrons, 27 protons, 27 electrons.
C) 15 neutrons, 12 electrons, 15 protons.
D) 16 electrons, 11 neutrons, 16 protons.