The correct answer is - b. 1993.
Even thought he European Union has its origins and basis from the 1950's and onward, it has been officially established as we know it nowadays in the year of 1993, in Maastricht, Netherlands.
It is a union of European countries, with the purpose of joint and supportive economies, open borders between the member states, political union, and also a fight against the nationalism on the continent and trying to make the multiple ethnic groups feel like Europeans (but hasn't seen any success whatsoever).
