Which Statement BEST Describes an Interaction in a Two-Way ANOVA

Multiple Choice

Which statement BEST describes an interaction in a two-way ANOVA?

A) The two independent variables have a combined effect on the dependent variable that is not present with either independent variable alone.
B) Both independent variables have a main effect.
C) No variable has a main effect.
D) The study is a within-subjects design, so all participants receive all levels of each independent variable.