What is the main difference between a one-way ANOVA and a two-way ANOVA in terms of variability?
a) One-way ANOVA considers the variability within groups only, while two-way ANOVA considers the variability within groups and also the interaction between groups.
b) One-way ANOVA considers the variability within groups and also the interaction between groups, while two-way ANOVA considers the variability within groups only.
c) One-way ANOVA does not consider any variability, while two-way ANOVA considers the variability within and between groups.
d) One-way ANOVA and two-way ANOVA are not different in terms of variability.