Across the period, generally ionization enthalpy increases.
IP is expected to increase in the same elemental order of third row as Mg,Al,Si,P and S.
But half-filled and fully-filled configuration are stable and may change the regular trend.
P having half-filled p-orbital has more IE1 than S.
Similarly, Mg has compltely filled s-orbital and more IE1 than Al, where the 3p electron is effectively shielded by 3s electrons.
Finally order should be Al<Mg<Si<S<P
Hence, (d) is the correct option.