Answer: Choice D) |K| = 57
------------------------------------------------------
Step-by-step explanation:
The notation |K| means "the number of items in set K". It is similar to the notation n(K). In this case, we simply add up all the values in the circle labeled K. There are four of these values which are 13, 8, 17, 19. Add up these values to get 13+8+17+19 = 57. So there are 57 items in set K.