6. Doreen has a utility function U(x,y)=2x+3y. The price of good x is $3, and the price of good y is $4. If Doreen's income is $120, how many units of good y would she consume if she chose the bundle that maximizes her utility subject to her budget constraint? a. 0 b. 10 c. 20 d. 30 e. None of the above.