Mark likes to have 1.5 portions of fries with each burger he eats. He does not eat burgers without fries nor fries without burgers. Let X be the quantity of portions of fries he consumes and Y the quantity of burgers. For simplicity assume that he can consume parts of portions of fries and parts of burgers. Suppose he has $12 to spend on fries and burgers. The price of a portion of fries is $1 and the price of a burger is $2.50. Now suppose that there is a shortage of beef and the price of burgers increases to $3.50. What is the price effect (PE), the substitution effect (SE) and the income effect (IE) on fries? Question 9 options: PE=-1.25; SE=0; IE=-1.25 PE=-0.9; SE=-0.9, IE=0 PE=-1.25; SE=-1.25; IE=0 PE=-0.9; SE=0, IE=-0.9