单项选择题
A.P(ξ>0)=P(ξ<0)B.P(ξ>0)<P(ξ≥0)C.P(ξ>0)<P(ξ>0)D.P(ξ>1)=P(ξ<1)
A.1/36B.2/36C.3/36D.4/36
A.0.25X1-0.25X2+0.25X3-0.25X4B.0.3X1-0.3X2+0.3X3-0.3X4C.0.25X1+0.25X2+0.25X3+0.25X4D.0.3X1+0.3X2+0.3X3+0.3X4