Final answer:
Civic nationalism fosters a sense of shared citizenship in a multination state by promoting equal rights and responsibilities for all citizens.
Step-by-step explanation:
Civic nationalism is a crucial factor in the unity of a multination state because it fosters a sense of shared citizenship among its diverse population. This means that civic nationalism promotes the idea that all citizens, regardless of their cultural background, have equal rights and responsibilities as members of the nation. It focuses on a common set of values and principles that bind people together as citizens of a particular country, rather than emphasizing a specific cultural or ethnic identity.