Which country is known as the Land of the Rising Sun?

Japan is known as the Land of the Rising Sun primarily due to its name in Japanese, which is "Nihon" or "Nippon." These terms can be translated to mean "origin of the sun," signifying Japan's geographic position to the east of the Asian continent where the sun rises. This phrase symbolizes not only the country’s location but also reflects its cultural identity and historical significance, particularly in the context of its mythology and literature. The nickname has been embraced widely and is also seen in Japan's flag, which features a red circle representing the sun on a white background.

The other options do not carry the same cultural or historical significance associated with the phrase "Land of the Rising Sun." China, while having many cultural and historical identities, is not referred to in this manner. Similarly, South Korea and Thailand have their own distinct names and cultural symbols that do not relate to this particular designation.