Question 11 (2 points) In 2015, the United Nations signed a new global climate change agreement in Paris. Around that time, the Pew Research Center conducted an international survey to explore the relationship between the level of concern over climate change and CO2 emissions per capita in each country. If the stated objective was to examine factors that may help explain opinions about global climate change worldwide, which of the following is the explanatory variable? A country's per capita CO2 emission The average of people's level of concern in all countries People's level of concern over global climate change in each country The average per capita CO2 emission in all countries