Consider the following reaction 8A+ 5B ---> 8C + 6D If [C] is changing at a rate of 4.0 mol L^(-1)*s ^(-1), at what rate is [B] changing? A -0.4 mol L^(-1)*s ^(-1) B -2.5 mol L^(-1)*s ^(-1) C -4.0 mol L^(-1)*s ^(-1) D -6.4 mol L^(-1)*s ^(-1) E. none of these, the change must be positive