Russ Tickman Is a Dairy Farmer

Russ Tickman is a dairy farmer. He consumes milk and other goods. His utility function is given by U(x, y) = y(x + 1) , where x is his milk consumption and y is his consumption of other goods. His initial endowment is 19 units of milk per day and no units of other goods. If the price of milk is $2 and the price of other goods is $1, how much milk does he consume?

A) 9 gallons
B) 38 gallons
C) 20 gallons
D) 14 gallons
E) 12 gallons