The place in the name belongs to a specific founding step.
The six founding countries were Belgium, the Federal Republic of Germany, France, Italy, Luxembourg and the Netherlands. They agreed on closer economic cooperation. The EEC was one of the communities from which today’s European Union later developed.
The question already tells you the subject: it names the European Economic Community. You therefore need the treaties that established this particular community, rather than just any treaty connected with Europe.
The other three answers
City names appear in many treaty titles. What matters is which community was established.
through the 'Hamburg Treaties'
“Hamburg Treaties” is not the name of the treaties establishing the EEC. The relevant connection is Rome and the Economic Community.
through the 'Paris Treaties'
“Paris Treaties” does not identify the treaties establishing the EEC asked about here. Do not confuse a familiar treaty name with the specific subject of the question.
through the 'London Treaties'
“London Treaties” does not match the EEC’s foundation either. These treaties were signed in Rome.
Six founding countries does not mean six present-day EU members.
The number six describes the historical beginning of this cooperation. Other countries joined later, and the treaties and institutions developed further. Historical founding numbers and current membership totals answer different questions.
The Treaties of Rome were signed on 25 March 1957 and entered into force on 1 January 1958. Euratom was established alongside the EEC. The question’s focus on the EEC does not make the second community an incorrect historical detail.
Treaties of Rome · European Union ↗EEC → Treaties of Rome → six founding countries.
Learn the treaty name and its subject together. This also helps with the reverse question about what the Treaties of Rome established.
Three words for this question
- der Gründerstaatfounding country
- A country involved when a group or community is established.
- der Vertragtreaty or agreement
- A binding agreement, here between countries.
- sich zusammenschließento join together
- To form a group or community together.