- Membership in the United Nations (UN) is governed by a set of parameters outlined in the UN Charter. To become a member of the UN, a state must meet certain criteria and fulfill specific obligations. These parameters can be summarized as follows:

a) It must be a state, it must be peace-loving:
One of the fundamental requirements for UN membership is that the entity seeking membership must be a state. According to international law, a state is defined as a politically organized entity with a permanent population, a defined territory, a functioning government, and the capacity to enter into relations with other states. Additionally, a state seeking membership must demonstrate a commitment to peace and be willing to resolve disputes peacefully.

b) It must accept the obligations to the Charter; it must be willing to carry out these obligations:
Another crucial parameter for UN membership is the acceptance of the obligations outlined in the UN Charter. The Charter serves as the foundational document of the UN, outlining the principles, purposes, and functions of the organization. By accepting the Charter, a state agrees to abide by its provisions and fulfill its obligations as a member of the UN. This includes respecting human rights, promoting peace and security, and cooperating with other member states.

c) It must be able to carry out these obligations:
In addition to accepting the obligations of the Charter, a state seeking UN membership must demonstrate the ability to fulfill these obligations effectively. This means that the state should possess the necessary resources, infrastructure, and capacity to implement the provisions of the Charter. It should have the ability to contribute to the work of the UN, participate in its various organs, and actively engage in international cooperation.

Considering the above parameters, the correct option is 'D' - all of the above. To become a member of the UN, a state must meet the criteria of being a state, being peace-loving, accepting the obligations of the Charter, and demonstrating the capacity to carry out these obligations effectively. These parameters ensure that the UN consists of states that are committed to peace, cooperation, and the promotion of international law and human rights.