函数y=x²-4x+3在闭区间[-1，m]上有最大值8，则实数m的值不可能的是（　　）

A．0

B．2

C．4

D．6

The period ranging from 1865 to 1914 has been referred to as （）in the literary history of the United States.

A．the Age of Enlightenment

B．the Age of Romanticism

C．New England Transcendentalism

D．the Age of Realism