I think it refers to the Council of Europe, founded in 1949 not the EEC. Britaoin was a founding member of the Council of Eruope, but only joined (the biggest mistake ever!) the EEC in 1973.

'The Council was officially founded on 5 May 1949 by the Treaty of London, which established the Council of Europe. The Treaty of London was signed by ten states: Belgium, Denmark, France, Ireland, Italy, Luxembourg, the Netherlands, Norway, Sweden and the United Kingdom. Many states followed, especially after the democratic transitions in central and eastern Europe during the early 1990s.'

The EU was only established in 1992 (Maastricht Treaty), before that was the EC or EEC based on the Treaty of Rome (1957).

Thanks a lot Eduardo , its all clear now

in the quiz of the old book it says Britain was one of the founder members of Europian Union, but the book in the market says its not. When britain joined Eu in 1973 how can it be the founder member of EU? Can any one clarify and if i am right then change the answer accordingly please?