Considering the available options, the events that could be a threat to a state’s sovereignty at the national scale while holding a region together at the global scale is "<u>Admittance into a supranational organization such as the European Union."</u>
<h3>What is a Supranational Organization?</h3>
A Supranational organization is a type of organization in which the members, usually the countries, surrender their power and autonomy on specific issues, precisely internal matters concerning all the members, to the organization's rulings.
The advantage of being a member of a Supranational organization is that it keeps countries together and formidable on a world scale.
For example, the European Union, where all the members vote to make decisions on issues concerning all the organization members.
Hence, in this case, it is concluded that the correct answer is option C. "<u>Admittance into a supranational organization such as the European Union."</u>
Learn more about European Union here: brainly.com/question/13929900