The correct answer is - southern Africa.
The coal fields found in the southern part of the African continent and the eastern part of the United States are a direct evidence that supports the theory of the continental drift. The reason for that is that the coal found in both locations is the same one, from the same type of trees, formed in the same period. All of those clues suggest that the continents were once merged together, as for starters, the type of tree that gave the basic material for the coal is the same, and trees that are totally the same is almost impossible to be found in separated continents as they will have some modifications that will distinguish them. The climate and period in which the coal is formed is also exactly the same, which also leads to the conclusion that there was once a large connected land mass.