Two counterfeit coins of equal weight are mixed with 8 identical genuine coins. The weight of each of the counterfeit coins is different from the weight of each of the genuine coins. A pair of coins is selected at random without replacement from the 10 coins. A second pair is selected at random without replacement from the remaining 8 coins. The combined weight of the first pair is equal to the combined weight of the second pair. What is the probability that all 4 selected coins are genuine?

**Answer Choices**

A. \dfrac{7}{11}

B. \dfrac{9}{13}

C. \dfrac{11}{15}

D. \dfrac{15}{19}

E. \dfrac{15}{16}