As East, you hold:
After 1NT-3NT, your partner leads the K as shown. Let's say you play low and the first trick goes as shown.
Then, partner plays the 9 and trick 2 goes as below. What do you conclude?
Partner started with KQJ109.
At tricks 2 and 3, declarer plays the A then the J to dummy (partner following). Next comes another diamond as shown below. You will have to make 3 discards on the diamonds. What will they be?
First a heart, then black cards.
First a low spade.
First the 9, then spades.
First the 9, then a heart and a club.