Owen and Simon Both Like Playing with Balls and Cars

Multiple Choice

Owen and Simon both like playing with balls and cars.Suppose B represents the number of balls,and C represents the number of cars.If Owen's utility function can be given by U(B,C) = 10B + 5C,and Simon's utility function can be given by U(B,C) = 6B + 6C,which of the following trades would be mutually beneficial?

A) Owen gives Simon 3 cars in exchange for 2 balls
B) Owen gives Simon 2 cars in exchange for 3 balls
C) Owen gives Simon 3 balls in exchange for 2 cars
D) Owen gives Simon 2 balls in exchange for 3 cars