The correct option is D Belgium
Cross-cutting differences occur when a type of social difference cross-cut another kind of social difference. For instance, Northern Ireland and the Netherlands, both had two different Christian groups. In Northern Ireland, Catholics were most likely to be poor while in the Netherlands, class and religion tend to cross-cut each other. In Belgium, constitutional reforms were made so that no one felt left out, and all the ethnic groups were given equal opportunities, unlike the case of Sri Lanka.