Good X is a normal good and its demand is given by Qxᵈ= a₀ + aXPX + aYPY + aMM +aHH. M represents income, Px represents the price of the good and Py represents a complement. Then we know
a. aH > 0.
b. aX > 0.
c. aY > 0.
d. aM > 0.