${\rm{p\pi }} - {\rm{p\pi }}$ multiple bonding is present in:
A. oxides of nitrogen
B. oxides of phosphorus
C. halides of nitrogen
D. halides of phosphorus

Hint: As we know, generally, the molecular orbital theory describes the bonding orbitals. The multiple bonding can be identified by the electronic configuration of the given element.

Complete step by step solution
We know that, ${\rm{p\pi }} - {\rm{p\pi }}$ multiple bonding present in that orbitals which have various bonds which are made by the overlapping of the ${\rm{p}}$ orbitals and it is perpendicular to the nuclear axis. The atomic number of nitrogen and oxygen is $7$ and $8$ respectively. The electronic configuration of nitrogen atom is ${\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}$, while the electronic configuration of oxygen is ${\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^4}$. Thus, both elements have ${\rm{p}}$ valence shell electrons. In the nitrogen and oxygen molecule, the valence ${\rm{p}}$ orbital is present. So, usually ${\rm{p\pi }} - {\rm{p\pi }}$ multiple bonding are shown or present in oxides of nitrogen. The two famous or renowned oxides of nitrogen are nitric oxide and nitrogen dioxide. They both are present in the gaseous state in the atmosphere. Usually, nitrogen oxides are formed or prepared in the reaction named as combustion. The general meaning of combustion reaction is burning the compounds.

Hence, the correct choice for this question is A that is oxides of nitrogen.

Note:
The bonding orbital generally describes through the molecular orbital (MO) theory. The bonding orbitals are those orbitals which show the interactions between the orbitals of one or more than two molecules.