Which of the following countries is NOT a G20 member?

The correct answer is Option (4) → Singapore

The G20 (Group of Twenty), formed in 1999, brings together the world’s major economies: 19 countries and the European Union. The 19 countries are Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the United Kingdom and the United States.

Singapore is not a member; it has often attended G20 summits as an invited guest country.