Veronal (5,5-diethylbarbituric acid, $\mathrm{C}{}_8\mathrm{H}{}_{12}\mathrm{N}{}_2\mathrm{O}{}_3$) is made by condensing diethyl diethylmalonate with urea in the presence of sodium ethoxide. How many moles of ethanol are eliminated per mole of veronal, and what functional group makes up the heterocyclic ring?

1. A2 mol of ethanol; a cyclic anhydride
2. B1 mol of ethanol; a cyclic ether
3. C2 mol of water; a lactone
4. D2 mol of ethanol; a cyclic ureide (two amide linkages to one urea carbon)