Concept:The UN generally avoids interfering in the internal political systems of member states.
Explanation:The UN works on issues such as climate change, human rights, and humanitarian aid.
However, it respects the principle of sovereign equality.
This means the UN does not usually try to remove or change oligarchical regimes, which are governments run by a small group.
The UN only acts against such regimes if they cause serious human rights abuses or endanger world peace.
So, oligarchical regimes are not a direct challenge the UN routinely addresses.
Answer:D. oligarchical regimes