选D
x^3-6x^2-x+6=0
x^2(x-6) -(x-6) =0
(x-6)(x^2-1) =0
(x-6((x-1)(x+1) =0
x1 =6,x2 =1,x3 = -1
所以,三个根的积是：
x1*x2*x3 = -6.