Which mixture of the solutions will lead to the formation of negatively charged colloidal $[AgI] I^{-}$ sol. ?

Question

( A ) 50 mL of 1M $AgNO_3$ + 50 mL of 2 M KI
( B ) 50 mL of 1M $AgNO_3$ + 50 mL of 1.5 M KI
( C ) 50 mL of 0.1 M $AgNO_3$ + 50 mL of 0.1 M KI
( D ) 50 mL of 2 M $AgNO_3$ + 50 mL of 1.5 M KI