Which of these is not a country?
Madrid is not a country – it is the capital and most populous city of Spain. The city has almost 3.3 million inhabitants and a metropolitan area population of approximately 6.5 million. It is the third-largest city in the European Union (EU), surpassed only by London and Berlin, and its monocentric metropolitan area is the third-largest in the EU, smaller only than those of London and Paris. The municipality covers 604.3 km2 (233.3 sq mi).
Yemen, officially the Republic of Yemen, is a country at the southern end of the Arabian Peninsula in Western Asia. It is the second-largest Arab sovereign state in the peninsula, occupying 527,970 square kilometres. The coastline stretches for about 2,000 kilometres.
Qatar is a peninsular Arab country whose terrain comprises arid desert and a long Persian (Arab) Gulf shoreline of beaches and dunes. Also on the coast is the capital, Doha, known for its futuristic skyscrapers and other ultramodern architecture inspired by ancient Islamic design, such as the limestone Museum of Islamic Art. The museum sits on the city’s Corniche waterfront promenade.
Cape Verde, or Cabo Verde, is a nation on a volcanic archipelago off the northwest coast of Africa. It’s known for its Creole Portuguese-African culture, traditional morna music and numerous beaches. Its largest island, Santiago, is home to the current capital, Praia. Santiago is also home to the old capital, Cidade Velha, with clifftop fortress Forte Real de São Felipe.