求指导本题解题过程，谢谢您！若总体X的分布律为: dfrac (X)(P)|dfrac (-1 0 2)({rho )^2 1-2theta (2-theta )} 参数 theta (0lt theta lt dfrac (1)(2)) 未-|||-知,X1,X2,X3,X 4为从总体中抽取的样本,样本观测值分别为: -1;0;0;-|||-2,则样本的联合分布律 ((X)_(1)=-1, X2=0, _(3)=0,(X)_(4)=2)= () ]-|||-A. (theta )^3(2-theta )(1-2theta ) B. theta (2-theta )(1-2theta )-|||-C. (theta )^2(2-theta )(1-2theta ) D. (theta )^3(2-theta )((1-2theta ))^2

求指导本题解题过程，谢谢您！