Which of the following is NOT an official language of the United Nations?

Japanese

The correct answer is Option (3) - Japanese

The United Nations has six official languages, which are English, French, Spanish, Chinese, Russian, and Arabic. These languages are used for official communication and documentation within the UN system. However, Japanese is not included among the official languages of the United Nations. While Japanese is an important language globally and is widely spoken and understood, it is not one of the designated official languages used by the UN for its official business and proceedings.