Which is an example of a regional security alliance? the u. s. agency for international development (usaid) the marshall plan the north atlantic treaty organization (nato) the united nations

An example of a regional security alliance is the North Atlantic Treaty Organization (NATO).

NATO is an intergovernmental military alliance governed by the North Atlantic Treaty, signed on April 4, 1949. The organization is a collective defense system, in which member states agree to defend any of its members if they are attacked by an external power.

d. it adversely affected american productivity