A two-factor ANOVA research study is used to evaluate the effectiveness of a new blood-pressure medication. In this two-factor study, Factor A is medication versus no medication and factor B is male versus female. The medicine is expected to reduce blood pressure for both males and females, but it is expected to have a much greater effect for males. What pattern of results should be obtained if the medication works as predicted? Chose only one answer.

a. a significant main effect for factor A (medication).

b. a significant interaction.

c. A significant main effect for factor B (gender)

d. none of the above.