Answer: Option (D) is the correct answer.
Explanation:
For a nucleus to be stable, there should be balance between the number of protons and number of neutrons.
That is, when there are too many protons or neutrons then it will cause an imbalance which will lead to disruption in binding energy from strong nuclear forces which will make the nucleus unstable.
Hence, closer is the number of neutrons to the number of protons more stable will be the nucleus.
Thus, we can conclude that a nuclei with 10 protons, 12 neutrons would be the most stable.
