The correct option is C They were related to themselves through blood and marriage.
The Habsburg Dynasty was an expansive region that included the Hungarians, Slovaks, Poles, Croats, Serbs, Jews, Gysies, Slovenes, etc. The aristocracy embraced ethnic diversity. The Habsburg higher nobility were related among themselves by ties of blood and marriage. This network of closed society helped them to preserve their political influence and economic privileges till 1918. The Catholic Church and the Habsburgs were allies. The Habsburgs were Catholic monarchs and supported the counter-reformation movement of the church.