Subject: mathqa
Question: a certain music store stocks 800 cellos and 600 violas . of these instruments , there are 110 cello - viola pairs , such that a cello and a viola were both made with wood from the same tree ( each tree can make at most one viola and one cello , so there are no pairs other than these 90 ) . if one viola and one cello are chosen at random , what is the probability that the two instruments are made with wood from the same tree ?
Option: 
A: 11 / 48,000
B: 3 / 1,600
C: 1 / 8,100
D: 2 / 45
Answer: A