Task: Question Answering
Input (English): Question: There are 15 slate rocks, 20 pumice rocks, and 10 granite rocks randomly distributed in a certain field. If 2 rocks are to be chosen at random and without replacement, what is the probability that both rocks will be slate rocks?

 Option A: 1/3

 Option B: 7/22

 Option C: 1/9

 Option D: 7/66

 Option E: 2/45
Output (English): Option D