Brunei — World Flags

The story behind the answer

Brunei is correct: its flag’s royal yellow reflects the Sultanate, while the diagonal black and white bands represent the two chief ministers, and the red crest with parasol, crescent, and uplifted hands carries the national motto.

Brunei Darussalam is a small, oil-rich nation on Borneo; the design dates to 1959 during British protection, with full independence in 1984. Memory tip: very few countries use a predominantly yellow flag—combine that with bold black/white diagonals and an Islamic emblem, and you’ve identified Brunei.