The correct answer is South America.
Explanation
The graph shows the change in forest cover across various regions such as Eastern and Southern Africa, Northern Africa, Western and Central Africa, East Asia, South and Southeast Asia, Western and Central Asia, Europe, Caribbean, Central America, North America, Oceania and South America of the world between 1990 and 2010 (divided into four groups 1990, 2000, 2005 and 2010). According to the graph the region with less change in forest cover is North America because through those years, there were close to 700.000 Ha; the region with the most increase of forest cover is East Asia because in 1990 there were close to 200.000 Ha and in 2010 there were close to 270.000 Ha, and the region with the most decrease of forest cover is South America because in 1990 there were close to 930.000 Ha and in 2010 there were close to 850.000 Ha. According to the above, the correct answer is South America.