Dependent List problem

I've got a table which has 2 columns and dependant lists created which work fine when the first item is selected then the second item is selected based on the first column. The problem is when the first column is then changed, it doesn't clear the data in the second column. Example file attached - so if at first Fruit, Apple is selected, then Fruit is changed to Vegetable, it still displays Apple in the second column. Is there any way of clearing the second column if the first is changed?
Thanks