Three sodium salts $\mathrm{NaA}$, $\mathrm{NaB}$ and $\mathrm{NaC}$ are made up as $0.10\mathrm{M}$ solutions. The conjugate acids have $K_a$ values $1.0\times 10^{-4}$ (HA), $1.0\times 10^{-6}$ (HB) and $1.0\times 10^{-8}$ (HC). Use $\mathrm{pH}=7+\frac{1}{2}(\mathrm{p}{K}_a+\log C)$ and $h=\sqrt{K_w/(K_{a}C)}$. Which statements are correct?

1. AThe pH of $\mathrm{NaC}$ exceeds that of $\mathrm{NaA}$ by 2.0 units.
2. BThe degree of hydrolysis of $\mathrm{NaC}$ is 10 times that of $\mathrm{NaA}$.
3. CThe pH of $\mathrm{NaB}$ is 9.5.
4. D$\mathrm{A}{}^{-}$ is the strongest conjugate base of the three.