The correct answer is option 1, gFe.

Let`s analyze each option to better understand why option 1 contains the most neutrons.

Option 1 represents an isotope of iron with a symbol "gFe". The letter "g" denotes that this is a generic symbol and represents various isotopes of iron. Iron has multiple isotopes with different numbers of neutrons, such as Fe-54, Fe-56, and Fe-57. Out of these isotopes, Fe-56 is the most abundant with 30 neutrons.

Option 2 represents an isotope of copper. Copper has two naturally occurring isotopes, Cu-63 and Cu-65. Cu-63 contains 34 neutrons, while Cu-65 contains 36 neutrons. Since option 1 (gFe) has more neutrons than either isotopes of copper, it is clear that option 1 contains more neutrons.

Option 3 represents zinc, which has only one naturally occurring isotope, Zn-64. Zn-64 contains 34 neutrons, which is less than option 1 (gFe).

Thus, out of the given options, option 1 (gFe) contains the most neutrons.