Question to consider: If ion B() had a very strong affinity for the resin, how would the elution time for ion B be affected?  If it takes forever to come off, would this be useful in trying to determine the quantity of that ion present?  When might this be useful? (Hint: go back to the introduction to the module and look at where ion-exchange is used...)  

As the affinity ion B has for the resin increases, the elution time would increase.  If the affinity becomes large enough, in essence anion B will stay on the column.  This phenomena is utilized in water filtration where ion exchange is used to remove particular ions from the sample.