The Correct Answer is Option 2, i.e. North America and Europe countries.
The North Atlantic Treaty Organization(NATO) is an intergovernmental military alliance of 30 North America and Europe countries
The organization, which was signed on 4 April 1949 , incorporates the North Atlantic Treaty.
NATO forms a collective defence mechanism in which its autonomous member states commit to joint protection in response to an attack from any outside party.
NATO Headquarters is in Evere, Brussels, Belgium, while Allied Command Operations Headquarters is situated close to Mons, Belgium.