The cyclic diene shown is treated with excess ozone and then with $\mathrm{H}{}_2\mathrm{O}{}_2$. Which structure is the only organic product?

The compound shown is cycloocta-1,5-diene. Cleaving both double bonds cuts the eight-membered ring into two identical four-carbon pieces, each ending in two carbonyl carbons. Oxidative work-up turns each aldehyde end into a carboxylic acid, so two molecules of butanedioic (succinic) acid form, which is a single compound.