Which statement is a central idea of the passage?
A. The American chestnut has disappeared, but it has been replaced with forests of oak, hickory, and poplar trees.
B. Despite many efforts to save the American chestnut, millions of trees have died in forests from Georgia to Maine.
C. The American chestnut had many uses, but a fungus from Asia ruined the chestnut wood and made the chestnuts inedible.
D. Although the American chestnut was nearly wiped out about 100 years ago by a fungus, some scientists are working to bring the tree back.