Answer
$Ag^{+}$
Work Step by Step
When NaCl is added to water, it dissociates into sodium and chloride ions. The chloride ions combine with Silver ions in the solution to form Silver Chloride, which is insoluble in water; hence, it precipitates. However, when KBr is added to water, it forms Potassium and Bromide ions. The bromide ions react with silver ions to form Potassium Bromide, which is soluble in water.
