the mechanic beneath combobox with same datasource

I have notice that when two combobox share the same datasource( for example a DataTable),they will share the same selected index.

I would like to know how this behaviour is implemented.

It feels like that DataTable has fire some sort of event when a 'current row' or 'active row' have change, and the comboboxs that bind to it capture the event and make coresponding changes. However, I saw that event when you use datasource like List, it works too.

Actually I would like to make a RadioButton to update synchronously with the two combobox, how should I implement that?

Questions I saw on the web mainly deal with how to de-synchronize the combobox with same datasource,like this Multiple Combo Boxes With The Same Data Source (C#), and this Binding two combo boxes to the same data source,that each combo will have individual behaviour, Share ComboBox DataSource.