Assertion (A): White $\mathrm{BaCO}{}_3$ dissolves in dilute HCl, but white $\mathrm{BaSO}{}_4$ does not. Reason (R): $\mathrm{CO}{}_3{}^{2-}$ is the conjugate base of a weak, unstable acid $\mathrm{H}{}_2\mathrm{CO}{}_3$ and is removed as $\mathrm{CO}{}_2$ by $\mathrm{H}{}^{+}$, while $\mathrm{SO}{}_4{}^{2-}$ is a very weak base and is not appreciably protonated by dilute HCl.

1. ABoth A and R are true and R is the correct explanation of A
2. BBoth A and R are true but R is not the correct explanation of A
3. CA is true but R is false
4. DA is false but R is true