单项选择题
A.1.2816,0.5244,0,-0.5244,-1.2816B.-1.2816,-0.5244,0,0.5244,1.2816C.1.2816,-0.5244,0,0.5244,-1.2816D.-1.2816,0.5244,0,-0.5244,-1.2816
A.0.866B.0.688C.0.686D.0.868
A.B.C.D.