A neighbouring country lies directly across the national border.
In this question, “neighbouring country” does not simply mean a country in the same part of the world. What matters is a shared border. Switzerland is one of the nine countries directly bordering Germany.
Switzerland is not a German federal state. It is a separate country. “European country” and “EU member” are also not equivalent: Switzerland is in Europe but is not a member of the European Union. This does not change its status as Germany’s neighbour.

The other three answers
The other three countries do not directly border Germany.
Hungary
Hungary is not among the countries sharing a border with Germany. Being reachable overland does not make it a direct neighbour.
Portugal
Portugal is a European country, but not Germany’s direct neighbour. “In Europe” describes a larger group than “bordering Germany”.
Spain
Spain also has no shared border with Germany. A familiar travel destination or EU member need not be a neighbouring country.
Borders, travel rules and currency are separate questions.
Switzerland participates in Schengen and uses the Swiss franc. This clearly illustrates that neighbouring status, shared travel rules and a shared currency are different things. One of these features does not automatically imply the others.
You do not need to memorise a border’s length for this question. Published distances can differ with the measurement method and the sections included. The reliable classification is enough here: Germany and Switzerland share a border.
Shared national borders · Federal Statistical Office ↗Switzerland is Germany’s neighbour despite not being an EU member.
Start with the shared border. Consider the EU, Schengen and currency when the question asks about them.
Three words for this question
- angrenzento border
- To lie directly next to another territory.
- der Nachbarstaatneighbouring country
- A country sharing a border with the country being considered.
- die Währungcurrency
- The monetary system of a country or shared currency area.
