Given below are two statements :

Statement I : The N - N single bond is weaker and longer than that of P - P single bond.

Statement II : Compounds of group 15 elements in +3 oxidation states readily undergo disproportionation reactions.

In the light of the above statements, choose the correct answer from the options given below

The large difference between the melting and boiling points of oxygen and sulphur may be explained on the basis of

The incorrect statement among the following is