A bag contains 5 green balls and 9 white balls. If two balls are drawn simultaneously, what is the probability that both balls are the same colour?  Choose the correct choice from the following:
A) 11 / 21  B) 17 / 42  C) 23 / 42  D) 46 / 91  E) 51 / 91

Rationale: "the total number of ways to draw two balls is 14 c 2 = 91 the number of ways to draw two green balls is 5 c 2 = 10 the number of ways to draw two white balls is 9 c 2 = 36 p ( two balls of the same colour ) = 46 / 91 the answer is d ."
Answer: D