Consider the following statements related to Ellingham diagram.I. It consists of plots of ΔfG∘vs T for formation of oxides of elements. 2xM(s)+O2(g)⟶2MxO(s)II. Each plot is a straight line. No effect of change in phase.III. In Ellingham diagram, the plots of ΔG∘ for oxidation of common metals and some reducing agents are givenIV. There is a point in a curve below which ΔG is negative (so MxO is stable). Above this point, MxO will decompose on its own.     Which of these statements are correct?