【单选题】

The SecurityCouncil is the most powerful body in the UN. It is responsible for maintaining international peace, and for restoring peace when conflicts arise. Its decisions are binding on all UN members. The SecurityCouncil has the power to define what is a threat to security, to determine how the UN should respond, and to enforce its decisions by ordering UN members to take certain actions. TheCouncil convenes (召集) any time there is a threat to peace.

A、representative from each member country who sits on theCouncil must be available at all times so that theCouncil can meet at a moment’s notice. The SecurityCouncil also frequently meets at the request of a UN member—often a nation with a grievance about another nation’s actions.
The SecurityCouncil has 15 members, five of which hold permanent seats. The assembly elects the other ten members for two-year terms. The five permanent members—the United States,Britain, France, Russia (formerly the Soviet Union), andChina—have the most power. These nations were the winning powers at the end of World War Ⅱ, and they still represent the bulk of the world’s military might.Decisions of theCouncil require nine votes.But any one of the permanent members can veto an important decision. This authority is known as the veto right of the great powers.As a result, theCouncil is effective only when its permanent members can reach a consensus (一致同意) .
TheCouncil has a variety of ways it can try to resolve conflicts among countries. Usually theCouncil’s first step is to encourage the countries to settle their disagreements without violence. TheCouncil can mediate a dispute or recommend guidelines for a settlement. It can send peacekeeping troops into a distressed are
A、If war breaks out, theCouncil can call for a ceasefire. It can enforce its decisions by imposing economic sanctions on a country, or through joint military action.
The last paragraph of this passage may be concluded with the statement that______.
A、UN gives priority to peaceful settlement of the conflicts among countries
B．the peacekeeping troops are most powerful in the conflicts between countries
C．economic sanction will be imposed on the countries involved in war
D．joint military action is the last resort of the SecurityCouncil in dealing with conflicts between among countries