There are 9 cards numbered from 1 to 9 in box A, and 5 cards numbered from 1 to 5 in box B. A box is randomly chosen, and a card is drawn. If the card is an even number, another card is drawn from the same box; if the card is an odd number, a second card is drawn from the other box.

a) What is the probability that both cards have even numbers?

b) If both cards have even numbers, what is the probability that they come from box A?

c) What is the probability that both cards have odd numbers?

d) Given that one card is odd and the other is even, what is the probability that they were drawn from box B?