Consider the relationship between y = political party preference (Democrat, Republican) and x1 = race

(Black, White) and x2 = gender. There is an association between y and both x1 and x2, with the Democrat preference being more likely for blacks than whites and for women than men.

(a) x1 and x2 are probably independent causes of y.

(b) The association between y and x1 is probably spurious, controlling for x2.

(c) Since both variables affect y, there is probably interaction.

(d) The variables probably satisfy a chain relationship.

(e) Race is probably a suppressor variable.

(f) None of the above.