which one of the following is not correctly matched?

United nations specialized agency	Headquarters
international civil aviation organization	Montreal
world trade organization	Geneva
united nations industrial development organization	Brussels
international fund for agricultural development	rome

To determine which pair is not correctly matched, let us check the actual headquarters for each United Nations specialized agency listed in the table:

1. International Civil Aviation Organization (ICAO):
Headquarters: Montreal, Canada.
Match status: Correctly matched.

2. World Trade Organization (WTO):
Headquarters: Geneva, Switzerland.
Match status: Correctly matched.

3. United Nations Industrial Development Organization (UNIDO):
Headquarters: Vienna, Austria (not Brussels).
Match status: Incorrectly matched.

4. International Fund for Agricultural Development (IFAD):
Headquarters: Rome, Italy.
Match status: Correctly matched.

Therefore, the pair that is not correctly matched is united nations industrial development organization - Brussels.