A solution contains $0.0100\mathrm{mol}$ each of $\mathrm{Ba}{}^{2+}$, $\mathrm{Sr}{}^{2+}$ and $\mathrm{Ca}{}^{2+}$. It is treated successively with (1) $\mathrm{K}{}_2\mathrm{CrO}{}_4$ in acetic acid buffer, giving $\mathrm{BaCrO}{}_4$; (2) $(\mathrm{NH}{}_4){}_2\mathrm{SO}{}_4$ on warming, giving $\mathrm{SrSO}{}_4$; (3) $(\mathrm{NH}{}_4){}_2\mathrm{C}{}_2\mathrm{O}{}_4$ giving $\mathrm{CaC}{}_2\mathrm{O}{}_4\cdot \mathrm{H}{}_2\mathrm{O}$ (each filtered off, precipitation complete). Molar masses: $\mathrm{BaCrO}{}_4$ 253, $\mathrm{SrSO}{}_4$ 183.6, $\mathrm{CaC}{}_2\mathrm{O}{}_4\cdot \mathrm{H}{}_2\mathrm{O}$ 146 $g/mol$. The total mass of the three precipitates is

1. A3.30$\mathrm{g}$
2. B5.83$\mathrm{g}$
3. C3.99$\mathrm{g}$
4. D5.65$\mathrm{g}$