单项选择题

gluLookAt(GLdouble eyex,GLdouble eyey,GLdouble eyez,GLdouble atx,GLdouble aty,GLdouble atz,GLdouble upx,GLdouble upy,GLdouble upz)函数中,确定目标点的值是()。

A.upx1,upy1,upz1
B.upx,upy,upz
C.eyex,eyey,eyez
D.atx,aty,atz