Which statement about António Guterres is incorrect?

The correct answer is Option 3-  He was a diplomat from the United States before becoming Secretary-General.

António Guterres is from Portugal, not the United States. He served as Portugal's Prime Minister and was later the UN High Commissioner for Refugees.

António Manuel de Oliveira Guterres (2017- ) Portugal; former Prime Minister of Portugal from 1995 to 2002; was the United Nations High Commissioner for Refugees during 2005–2015; President of the Socialist International from 1999 to 2005. He is serving as the ninth Secretary–General of the United Nations.