Ethyl acetoacetate has $\mathrm{p}{K}_a=10.7$. For which bases is the conversion of ethyl acetoacetate into its enolate essentially complete (take $\log K\ge 4$)? ($\mathrm{p}{K}_a$ of conjugate acids: ethanol 15.9, water 15.7, $\mathrm{H}{}_2\mathrm{CO}{}_3$ 6.4, $\mathrm{HCO}{}_3{}^{-}$ 10.3.)

1. A$\mathrm{NaOC}{}_2\mathrm{H}{}_5$
2. B$\mathrm{NaOH}$
3. C$\mathrm{NaHCO}{}_3$
4. D$\mathrm{Na}{}_2\mathrm{CO}{}_3$