Answer:
C) North Atlantic Treaty Organisation (NATO)
Step-by-step explanation:
North Atlantic Treaty Organisation was military organisation formed in 1949 to counter the communist aggression. Initially there were 29 European and North American countries that signed the treaty. It provided them with a system of collective defence against an attack by any external party (i.e Soviet Union)
Its headquarter is located in Brussels, the headquarter of allied command Operation is in Mons, Both Mons and Brussels are in Belgium. The military spending of all the NATO members is over 70 % of the global military spending.