Which statements about the following anions are correct? (pKa of conjugate acids: ethane about 50, ethene about 44, ethyne 25, ammonia 38, water 15.7)

1. A$\mathrm{HC}\equiv \mathrm{C}{}^{-}$ is a weaker base than $\mathrm{CH}{}_2=\mathrm{CH}{}^{-}$
2. B$\mathrm{CH}{}_3\mathrm{CH}{}_2{}^{-}$ is a stronger base than $\mathrm{CH}{}_2=\mathrm{CH}{}^{-}$
3. C$\mathrm{NH}{}_2{}^{-}$ can deprotonate ethyne almost completely
4. DSodium acetylide can be prepared by adding ethyne to aqueous $\mathrm{NaOH}$ (conjugate acid of $\mathrm{OH}{}^{-}$ is water, pKa 15.7)