Ted and Joe each consume peaches, x, and plums, y. The consumers have identical utility functions, with Together, they have 10 peaches and 10 plums. Verify whether each of the following allocations is on the contract curve:
a) Ted: 8 plums and 9 peaches; Joe: 2 plums and 1 peach.
b) Ted: 1 plum and 1 peach; Joe: 9 plums and 9 peaches.
c) Ted: 4 plums and 3 peaches; Joe: 6 plums and 7 peaches.
d) Ted: 8 plums and 2 peaches; Joe: 2 plums and 8 peaches.