Arnold consumes goods x and y. His utility function is U(x, y) = x^2y. He is endowed with 30 units of x and 12 units of y. The price of x is $4 and the price of y is $8.

Arnold will sell at least 5 units of x but fewer than 10 units of x Arnold will sell fewer than 5 units of x

Arnold will buy 5 or more units of y

Arnold will buy fewer than 5 units, of x

Arnold will buy at least 5 units of x

Which answer is right, and please show all work. Thank you.