Let p be a probability function on set S, where S = (a

_{1}, a_{2}, a_{3}, a_{4}). Find P(a_{1}) if P(a_{2}) = (frac{1}{3}), p(a_{3}) = (frac{1}{6}) and p(a_{4}) = (frac{1}{5})-
**A.**

(frac{7}{3}) -
**B.**

(frac{2}{3}) -
**C.**

(frac{1}{3}) -
**D.**

(frac{3}{10})