Which organization is an example of a group that practices explicit collusion?

OPEC, or the Organization of the Petroleum Exporting Countries, is a prime example of a group that practices explicit collusion. Explicit collusion occurs when firms or organizations come together and formally agree on certain actions, such as fixing prices or limiting production in order to maximize their profits. In the case of OPEC, member countries coordinate their oil production levels and set target prices for crude oil, allowing them to exert considerable influence over the global oil market. This coordinated approach helps them to maintain higher prices than they would be able to achieve individually, reflecting the essence of collusion where cooperation between firms leads to market control.

In contrast, organizations like NATO, the WTO, and the UN serve different purposes. NATO is primarily a military alliance; the WTO is focused on promoting and regulating international trade policies; and the UN deals with a wide range of global issues including peace, security, and humanitarian concerns. None of these organizations engage in explicit collusive practices related to market manipulation or price setting in the same way OPEC does with oil. Thus, OPEC stands out as the correct answer, demonstrating the concept of explicit collusion through its orchestrated efforts among member nations to manage oil production and pricing collaboratively.