Read this: Nigeria's foreign policy was tested in the 1970s after the country emerged united from its own civil war. It supported movements against white minority governments in the Southern Africa sub-region. Nigeria backed the African National Congress (ANC) by taking a committed tough line with regard to the South African government and their military actions in southern Africa. Nigeria was also a founding member of the Organisation for African Unity (now the African Union), and has tremendous influence in West Africa and Africa on the whole. Nigeria has additionally founded regional cooperative efforts in West Africa, functioning as standard-bearer for the Economic Community of West African States (ECOWAS) and ECOMOG, economic and military organisations, respectively.

What group was Nigeria a founding member of?
What is the answer? (If it cannot be answered, return "unanswerable")
Organisation for African Unity