The correct answer is - Brazil.
The Amazon jungle is in fact the largest tropical rainforest in the world. Most of it is in the territory of the biggest country in South America, Brazil. More specifically, it occupies the northern half of the country. Unfortunately, the Amazon jungle is facing a huge problem because every year it is becoming smaller and smaller, and this is due to the human activities. It is a rainforest that has to be protected, sooner rather than later, because it is the forest that releases the most oxygen in the atmosphere (thus the nickname - the Earth's lungs) which is extremely important for the life on the Earth, including the humans.