The cis diol shown is cleaved with excess periodic acid, and the product is then stirred with aqueous $\mathrm{NaOH}$ and heated, which causes an intramolecular aldol condensation. Which structure is the final product?

The compound is cis-1,2-dimethylcyclohexane-1,2-diol. $\mathrm{HIO}{}_4$ cleaves the ring C1-C2 bond to give the diketone octane-2,7-dione. With base, the enolate formed at C3 attacks the C7 carbonyl, closing a five-membered ring (C3-C4-C5-C6-C7), and dehydration gives 1-acetyl-2-methylcyclopentene. Attack from the C1 methyl would give a seven-membered ring, which is less favourable, and the aldol adduct without loss of water is not the condensation product.