Which of the following statements are correct?

(P) structure is not allowed because octet around O cannot be expanded.

(Q) ${\mathrm{H}}_2{\mathrm{O}}_2$ is an ionic compound.
(R) In ${\mathrm{B}}_2$molecule, the highest occupied molecular orbital is σ molecular orbital.
(S) The $\mathrm{lp}-\mathrm{bp}$ repulsion, is stronger than $\mathrm{bp}-\mathrm{bp}$ repulsion.
 

The $\mathrm{lp}-\mathrm{bp}$ repulsion, is stronger than $\mathrm{bp}-\mathrm{bp}$ repulsion statement is correct.
Because it is not shared by two nuclei, a lp takes up more room than a $\mathrm{bp}$, and the repulsion between the two is stronger between the lp and bp than between the bp and $\mathrm{bp}$. Bond angle distortion because to the presence of lp results in a deviation from the optimum form.
Hence, option C is correct.