what is a definition of citizenship?

a having been born in a country
b being a full and equal member of a nation
c having pledged to respect and support a government's values
d fulfilling all the responsibilities and having all the rights of living in a society

All of the options you provided can be considered components of citizenship, but the most comprehensive definition would be:

d) Fulfilling all the responsibilities and having all the rights of living in a society.

Citizenship encompasses more than just being born in a country (option a), as it can also be acquired through naturalization or other means. Being a full and equal member of a nation (option b) is a crucial aspect of citizenship, as it implies equality, inclusion, and participation in the political and social affairs of the country. Additionally, while option c highlights the importance of respecting and supporting a government's values, it is just one aspect of citizenship. Overall, option d encompasses the broadest understanding of citizenship as it includes both rights and responsibilities, making it the most suitable choice.