Rút gọn biểu thức sau: \(P = \dfrac{{{a^{\frac{4}{3}}}\left( {{a^{ - \frac{1}{3}}} + {a^{\frac{2}{3}}}} \right)}}{{{a^{\frac{1}{4}}}\left( {{a^{\frac{3}{4}}} + {a^{ - \frac{1}{4}}}} \right)}}.\)
A.\(P = {a^{\frac{1}{2}}}\)
B.\(P = {a^{ - \frac{2}{3}}}\)
C.\(P = a\)
D.\(P = {a^{\frac{5}{3}}}\)