Correct Answer: (d) Vietnam
Solution:The Shanghai Cooperation Organization (SCO), is a Eurasian political, economic, and security alliance, the creation of which was announced on 15th June, 2001 in Shanghai, China by the leaders of China, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan. The original five members, with the exclusion of Uzbekistan, were previously members of the Shanghai Five group, founded on 26th April, 1996. Since then, the organization has expanded its membership to nine States when India and Pakistan joined SCO as full members in 2017 and Iran joined as full member in 2023.