The correct option is C 100 mL 0.1 M AgNO3 +100 mL 0.2 M KI
Milli moles of AgNO3=100×0.1=10
Milli moles of KI=100×0.2=20
KI is in excess.
AgNO3(aq)+KI(aq)→AgI(s)↓+AgNO3(aq)
AgI gets precipitated.
The precipitated silver iodide adsorbs iodide ions (I−) from the dispersion medium and negatively charged colloidal sol is formed AgI/I−
Therefore, correct option is (c)