In a CRD with a qualitative factor A at 2 levels and a quantitative factor B at 3 levels, the researcher wants to know if the quadratic trend in the mean responses across the levels of factor B differ for the two levels of factor (A). Which of the following contrasts would address this question?

A. L=u31 - 2u32 + u33 + u21 - 2u22 + u23
B. L=u11 - 2u12 + u13 - u21 - 2u22 - u23
C. L=u11 - u12 - u13 - u21 + u22 + u23
D. L=u11 - u12 + u31 - u23
E. None of them appropriate.