Jerome wrote each of the integers 1 through 20, inclusive, on separate index cards. He placed the cards in a box, then drew cards from the box one at a time at random, without returning the cards he had already drawn to the box. In order to ensure that the sum of all the cards he drew was EVEN, how many cards did Jerome have to draw?
A. 19
B. 12.
C. 11
D. 10
E. 03