单选题 If x2+9x-3=3x2+2x(4-x), then x2=
A. 2
B. 3
C. 4
D. 9
E. 16

【正确答案】 D
【答案解析】The statement 3x2+2x(4-x) can be restated as x2+8x. Thus, the original equation can be restated as x=3, so x2=9.