Who was the United States Ambassador to the United Nations?

The correct answer identifies Ambassador Susan Rice, who served as the United States Ambassador to the United Nations from 2009 to 2013 under President Barack Obama. During her tenure, she played a significant role in numerous international issues, including global security challenges and humanitarian crises. Rice was known for her advocacy for human rights, her work in promoting multilateral diplomacy, and her role in the response to the conflict in Syria as well as addressing issues in Africa.

While John Bolton, Nikki Haley, and Linda Thomas-Greenfield also held the ambassadorial position at different times, this question specifically references Susan Rice's term. John Bolton served later, from 2005 to 2006, during the George W. Bush administration. Nikki Haley was the ambassador from 2017 to 2018 under President Donald Trump, and Linda Thomas-Greenfield took on the role in 2021 under President Joe Biden. Each contributed to the UN in distinct contexts and policies, but Susan Rice is the correct answer in the context of the question as she was the ambassador during the specified period in the Obama administration.