Consumers A and B consume two goods,XandY. There is no production. The total endowments of goodXand Y are equal. A's utility function isU(xA,yA) = min{xA,yA} and B's utility function isU(xB,yB)=max{xB,yB}. In an Edgeworth box for consumers A and B, the set of Pareto optimal allocations is

a.

the edges of the box and the main diagonal.

b.

the edges of the box.

c.

the main diagonal.

d.

both diagonals.

e.

the whole Edgeworth box.