The correct answer is e) noble gases.
Noble gases are unique because they possess a complete octet in their highest occupied energy levels, meaning their outermost s and p orbitals are fully filled. For instance, in the case of neon (Ne), the electron configuration is 1s² 2s² 2p⁶, which shows that both the s and p orbitals of the second energy level are filled. This stability of a full outer shell is what makes noble gases largely unreactive compared to other elements.
In contrast, alkali metals (a) have one electron in their outermost s orbital, alkaline earth metals (b) have two, transition metals (c) have incompletely filled d orbitals, and halogens (d) have seven electrons in their outermost p orbitals, which means they are one electron short of a full p orbital. Thus, none of these groups have fully filled s and p orbitals in their highest energy levels like the noble gases do.