In a 2-way analysis of variance, when we say we have a MAIN EFFECT, we mean that: A. The main source of variance in our experiment is produced by Factors A and B B. The effect of one independent variables on a dependent variable is significant, taking into account the second independent variable C. The effect of one independent variable on a dependent variable differs as a function of a second independent variable D. The means for the levels of Factor A after collapsing over Factor B are significantly different from one another