Which Japanese-occupied Southeast Asian country was renamed 'Syonan-to' during the Second World War, before reverting and later becoming an independent nation that briefly joined Malaysia in 1963?

• A Brunei
• B Burma
• C Indonesia
• D Singapore ✓

Singapore fell to Japan in February 1942 and was renamed Syonan-to ('Light of the South'); it joined the Federation of Malaysia in 1963 but separated amicably in 1965.