The correct answer is Seoul, the capital and largest city of South Korea. Seoul lies in the northwest of the country along the Han River and has served as the political, economic and cultural centre of Korea for centuries, a role it retained after the division of the Korean Peninsula in 1948 when the Republic of Korea (South Korea) was established with Seoul as its capital. The three distractors are all genuine and significant South Korean cities, chosen deliberately because they are large enough to plausibly be mistaken for the capital. Busan is South Korea's second-largest city and its largest port, a major hub for international shipping and trade, but it has never functioned as the national capital. Incheon, located just west of Seoul, is home to the country's principal international airport and is itself a large metropolitan city, yet its prominence is tied to aviation and logistics rather than governance. Daegu is a major inland industrial city known historically for textiles, and while significant regionally, it likewise carries no capital status. A common exam confusion is assuming that any sufficiently large or internationally recognisable city must be a country's capital; this is especially true for Busan, which many students encounter first through its port or film festival and assume it holds administrative primacy. Historically, Seoul has carried various names across dynasties, including Hanseong and Gyeongseong under Japanese colonial rule (1910–1945), before adopting the name Seoul after Korea's liberation. Revision takeaway: fix Seoul firmly as South Korea's capital, and mentally separate it from Busan (port hub), Incheon (airport hub) and Daegu (industrial hub), none of which hold capital status.
