A Giffin good is not correctly described by which of the following?

Question

A)A Giffin good must be an inferior good.
B)A Giffin good must be such that the income effect and the substitution effect move in opposite directions, and the income effect outweighs the substitution effect.
C)A Giffin good must be such that the substitution effect outweighs the income effect for an inferior good.
D)A Giffin good must have an upward-sloping demand curve.

I chose C)