Answer:
d. Mg²⁺
Explanation:
c. K⁺
d. Mg²⁺
Based on the Bohr's atomic model, the atom has electrons (Mass 0; Charge -1), protons (Mass 1; Charge +1) and neutrons (Mass 1; Charge 0).
The atomic number is equal to the number of protons. That means there are 10 protons. As the Neon is netural, the amount of electrons must be 10.
A neutral atom of Mg has 12 electrons, that means the Mg²⁺ has 10 electrons the same than Ne.
Right option is: