Which is an example of a cultural bond in a nation-state? a holiday tradition a common language a favorite place a shared ancestry

A shared ancestry would not be enough and it would also not be a "cultural" bond - this is not the right answer.

A favorite place is not something that will bring people close enough - so it's also not the correct answer.

The other two answers are both correct, but "a common language" is a much stronger bond, so if you can choose only one answer - choose this one (but both are correct).