Consider the Following Multiplicative Demand Function Where Q_D = Quantity $$Q _ { D } = 1.6 \mathrm { P } ^ { - 15 } \mathrm { Y } ^ { 2 }$$

Consider the following multiplicative demand function where Q_D = quantity demanded,P = selling price,and Y = disposable income: $$Q _ { D } = 1.6 \mathrm { P } ^ { - 15 } \mathrm { Y } ^ { 2 }$$ The coefficient of Y indicates that (all other things being held constant) :

A) for a one percent increase in disposable income,quantity demanded would increase by .2 percent
B) for a one unit increase in disposable income,quantity demanded would increase by .2 units
C) for a one percent increase in disposable income quantity demanded would increase by .2 units
D) for a one unit increase in disposable income,quantity demanded would increase by .2 percent
E) none of the above