At the End of the Twentieth Century,the World Faced the Loss

At the end of the twentieth century,the world faced the loss of more species than at any time since the end of the last Ice Age.Of the recorded species of birds and animals,approximately

A) 1 percent are at risk of extinction.
B) 3 percent are at risk of extinction.
C) 5 percent are at risk of extinction.
D) 7 percent are at risk of extinction.