In an exchange economy, there are two people, A and B, and two goods, x and y. The utility functions of A and B are given by uA=xAyA and uB=xByB. Person A starts with 6,000 units of x and zero units of y. Person B starts with?
a) 0 units of x and 6,000 units of y
b) 6,000 units of x and 0 units of y
c) 3,000 units of x and 3,000 units of y
d) 9,000 units of x and 9,000 units of y