Final answer:
Prague is located in the Czech Republic, a country in Central Europe known for its rich history and medieval architecture.
Step-by-step explanation:
Prague is the capital and largest city of the Czech Republic. It is known for its unique medieval architecture and historical significance. The city's establishment dates back to the Romanesque era and has been flourishing since the Gothic, Renaissance, and Baroque periods. One notable historical landmark in Prague is the Vyšehrad Castle, which is surrounded by massive walls and sited on a cliff above the Vltava River. Regarding Czech history, it is notable that the Czech Republic and Slovakia were once a unified state, known as Czechoslovakia, until they split into two separate countries on January 1, 1993. Therefore, the correct answer to the question is d) Czech Republic.