Which of the following is an example of a country that is no longer in existence?

Burma is an example of a country that is no longer in existence under that name, as it has officially been renamed Myanmar. The country's name change reflects changes in its governance and the efforts to establish a national identity distinct from its colonial past. Though the territory and people remain, the name "Burma" is considered outdated and is often associated with the period prior to the military junta's rule and subsequent reforms.

In contrast, South Korea, Germany, and Japan continue to exist as recognized sovereign states. South Korea has maintained its identity since its establishment post-World War II, while Germany is a unified country since 1990 following the reunification of East and West Germany. Japan has been a continuous state with its historical name and governance. Thus, while all the other options represent states that remain in existence and have distinct political entities today, Burma's shift to Myanmar signifies that it is no longer recognized by its former name.