Which of the following reagent(s) can be used to distinguish between NiI2(en)2Cl2 and NiCl2(en)2I2?

AgNO3 gives white PPt of AgCl soluble in ammonia but AgI is yellow ppt insoluble in ammonia. PbNO3 gives white PPt of PbCl2 with Cl− but yellow PPt with I−.Chlorine water liberates Iodine from I−which gives violet colour in CCl4 or blue colour with starch but Cl− has no reaction.NaNO2 can liberate I2 from I-in acid medium but cannot liberate Cl2 from Cl-