Which mixture of the solutions will lead to the formation of negatively charged colloidal  [AgI]I -sol?

If colloidal sol of AgI is prepared by adding KI solution to AgNO3 till KI is in slightly  excess, iodide ion (I-) will be adsorbed on the surface of AgI thereby giving a negative charge to the sol.In second option 50 X 10-3 moles of AgNO3  is mixed with 75 X 10-3  moles of KI. KI is excess In third option 50 X 10-3 moles of AgNO3  is mixed with 100 X 10-3  moles of KI ..KI is excess   AgI  +  I-       ⟶      AgI:I-          (from KI)         Negative Sol