Which of the following is not an official language of Bosnia and Herzegovina?

Herzegovinan is not an official language of Bosnia and Herzegovina.

Bosnia and Herzegovina sometimes called Bosnia-Herzegovina, and often known informally as Bosnia, is a country in Southeastern Europe located on the Balkan Peninsula. Sarajevo is the capital and largest city. It is bordered by Croatia to the north and west; Serbia to the east; Montenegro to the southeast; and the Adriatic Sea to the south, with a coastline about 20 kilometres (12 miles) long surrounding the town of Neum.

Bosnia's constitution does not specify any official languages. However, academics Hilary Footitt and Michael Kelly note that the Dayton Agreement states that it is "done in Bosnian, Croatian, English and Serbian", and they describe this as the "de facto recognition of three official languages" at the state level. The equal status of Bosnian, Serbian and Croatian was verified by the Constitutional Court in 2000.