A box contains 10 pairs of shoes (20 shoes in total). If two shoes are selected at random, what is the probability that they are matching shoes?
A.fff\(\frac{1}{190}\)/fff
B.fff\(\frac{1}{20}\)/fff
C.fff\(\frac{1}{19}\)/fff
D.fff\(\frac{1}{10}\)/fff
E.fff\(\frac{1}{9}\)/fff
我的答案：
