Q. Consider the following countries:

1. Argentina
2. Brazil
3. Ecuador
4. Peru

Which of the above countries share the Amazon river basin?
Answer: Only 2, 3 and 4
Notes: The Amazon river basin is shared by Brazil, Ecuador, and Peru among the given options. Argentina does not share the Amazon basin. The basin is primarily spread across Brazil, Peru, Colombia, Ecuador, Bolivia, Venezuela, Guyana, and Suriname, covering about 40% of South America.