The correct answer is option 3 - 14.
To determine the number of neutrons in an atom, we need to know its atomic number and mass number.
In the given atom 13A127, the atomic number is 13. The atomic number represents the number of protons in the nucleus of an atom. In a neutral atom, the number of protons is equal to the number of electrons, so the atomic number also represents the number of electrons.
The mass number, represented as A, is the sum of the number of protons and neutrons in the nucleus.
To calculate the number of neutrons, we subtract the atomic number (number of protons) from the mass number. In this case, 127 - 13 = 114 neutrons.
Therefore, the correct number of neutrons in 13A127 is option 3 - 14.