One Key Political Area of ________ Has Been ______ Designed

One key political area of ________ has been ______ designed to tackle climate change. Predominately lead by the _________, a number of high profile conferences have been held over the last few decades, with varied success, due to issues such as differing perspectives on issues from emerging ________.

A) Sustainability, Tariffs, European Union, Countries
B) Sustainability, Legislation, United Nations, Economies
C) Global governance, Tariffs, United Nations, Countries
D) Global governance, Legislation, European Union, Economies