Two cards are dealt from a deck of four red cards labeled A, B, C, D and four green cards labeled A, B, C, D. A winning pair is two of the same color or two of the same letter. What is the probability of drawing a winning pair?
Answer Choices
A. \dfrac{2}{7}
B. \dfrac{3}{8}
C. \dfrac{1}{2}
D. \dfrac{4}{7}
E. \dfrac{5}{8}