Which one of the following statements is correct ?

Question

( A ) Manganese salts give a violet borax-bead test in the reducing flame
( B ) On boiling a solution having $K^+, \; Ca^{2+}$ and $HCO_3^-$ ions we get a precipitate of $K_2Ca(CO_3)_2$
( C ) Ferric ions give a deep green precipitate on adding potassium ferrocyanide solution
( D ) From a mixed precipitate of $AgCl$ and $AgI$, ammonia solution dissolves only $AgCl$