Two distinct numbers a and b are chosen randomly from the set \left\{2,2^{2}, 2^{3}, \ldots, 2^{25}\right\}. What is the probability that \log _{a} b is an integer?
Answer Choices
A. \dfrac{2}{25}
B. \dfrac{31}{300}
C. \dfrac{13}{100}
D. \dfrac{7}{50}
E. \dfrac{1}{2}