Final answer:
The noble gases, including helium, neon, argon, and xenon, have electron configurations where the highest occupied energy levels have completely filled s and p sublevels, making them stable and non-reactive according to the octet rule.
Step-by-step explanation:
The noble gases such as helium, neon, argon, and xenon share a common characteristic in their electron configurations. What they have in common is that in the highest occupied energy level, both the s and p sublevels are completely filled. This configuration contributes to their low reactivity and stability, as it adheres to the octet rule, which posits that atoms are most stable when they have eight electrons in their valence shell. Noble gases are therefore unreactive because they already have a full outer shell of electrons, making it unnecessary for them to gain or lose electrons to achieve stability.
The most stable configurations are those with full energy levels, such as the noble gases that do not react easily with other elements. The octet rule refers to the desire of elements to have full valence shells resembling noble gases. It's important to note that the Aufbau Principle guides the filling of sublevels and orbitals with electrons in order of increasing energy. Thus, we can confirm that choice 'c' is correct: In the highest occupied energy level, the s and p sublevels are completely filled.