More Than One Independent Variable Researchers Recently Evaluated the Impact

More Than One Independent Variable Researchers recently evaluated the impact of smoking and alcohol consumption on cardiovascular disease.They found that the incidence of cardiovascular disease was higher among women who smoked and consumed alcohol than among those who only smoked, only consumed alcohol, or did neither.This finding illustrates

A) a higher-order interaction.
B) a main effect.
C) an interaction.
D) two main effects.