Step 1: Understanding Nuclear Stability
In nuclear physics, a stable nucleus generally has an even number of protons and neutrons.
This configuration leads to a more stable nuclear structure due to paired interactions between protons and neutrons.
Step 2: Explanation of Other Options
Option (a) is incorrect because the number of electrons does not affect the stability of the nucleus, and a nucleus cannot have an odd number of electrons while being neutral.
Option (c) is incorrect because a nucleus with an even number of neutrons and odd protons is typically unstable.
Option (d) is incorrect because a nucleus with both odd protons and neutrons is also usually unstable.
Step 3: Conclusion
Thus, a stable nucleus typically has an even number of protons and neutrons.