The correct answer is A: Today, Germany and Italy are politically unified nations.
In the 17th century, Germany and Italy were not unified nations and were scattered in many regions that were politically, ideologically or ethnically divided. Today, both of them are politically unified nations each one.
B is incorrect because Europe does not have more multi-ethnic kingdoms nowadays than it did in the 17th century. Actually, the amount of kingdoms Europe has nowadays is very few.
C is incorrect because political boundaries do not follow <u>strictly</u> physical geographic features. Some do, but some don't.
Finally, D is incorrect because neither physical geography nor religion solely define European nations today.