Switzerland is correct for C. The question of naturalization as Swiss is decided very regionally there. Recently a British woman, who satisfied all other conditions, was denied their passport by a local referendum. Apparently she had created a local stir by objected too strongly against the use of cow bells !!Well the Swiss vote on just about everything going, so I guess that could be the clue to C.
Only another 6 to go. Of course my clues don't give much away, unless you know which women in Europe I find the sexiest (unlikely) - and it's not the Germans ! However - which country has the highest rate of naturalization in Europe (and compulsory voting afterwards), and who is Lionel ?