Here are the answers to the subsidiary questions in my Christmas Competition.
3. Look only at the East hand. After opening one diamond, what should he rebid when West responds (a)
The answers are: (a) one spade; (b) two spades (although three spades isn't wrong); (c) pass (although two clubs could work out well); (d) three clubs; (e) pass; (f) three no-trump (warning partner of good spades).