Respuesta :
Choice a : Explains what the nations need to do and elaborates some.
--wrong answers--
Choice b only gives a statement of what the nations need to do.
Choice c is a question.
--wrong answers--
Choice b only gives a statement of what the nations need to do.
Choice c is a question.
The answer is A. All nations must unite to address the 4 main causes of global warming: natural causes, pollution, increase in population, and deforestation.