Which best explains why elements with a completely full outer shell of electrons do not usually bond with other elements to form compounds?

a.
a full outer shell of electrons indicates a stable state, making the formation of compounds unnecessary. the full outer shell was obtained by releasing electrons instead of forming a compound.

b.
these elements have obtained electrons from other elements without bonding to create a full outer shell of electrons, and a stable state.

c.
elements with a completely full outer shell of electrons are in their most stable state. therefore, achieving stability through the formation of compounds is not necessary.

d.
because electrons orbit some atoms in three dimensional space, they move to different orbitals to stabilize the atom, making the formation of compounds unnecessary.
explain.