Which one of the following statements is correct?

Options

1. AFrom a mixed precipitate of $\mathrm{AgCl}$ and $\mathrm{AgI}$, ammonia solution dissolves only $\mathrm{AgCl}$.
2. BFerric ions give a deep green precipitate on adding potassium ferrocyanide solution.
3. COn boiling a solution having $\mathrm{K}^{+}, \mathrm{Ca}^{2+} and$\mathrm{HCO}_{3}^{-}$ions we get a precipitate of$\mathrm{K}_{2} \mathrm{Ca}$\left(\mathrm{CO}_{3}\right)_{2}$
4. DManganese salts give a violet borax bead test in the reducing flame.