Hàm số \(y = \tan x - \cot x + \cos \dfrac{x}{5}\) có đạo hàm bằng:

A. \(\dfrac{1}{{\cos x}} - \dfrac{1}{{\sin x}} + \dfrac{1}{5}\sin \dfrac{x}{5}\) 

B. \(\dfrac{1}{{{{\cos }^2}x}} + \dfrac{1}{{{{\sin }^2}x}} - \dfrac{1}{5}\sin \dfrac{x}{5}\) 

C. \(\dfrac{1}{{{{\cos }^2}x}} - \dfrac{1}{{{{\sin }^2}x}} - \dfrac{1}{5}\sin \dfrac{x}{5}\) 

D. \(\dfrac{1}{{\cos x}} + \dfrac{1}{{\sin x}} + \dfrac{1}{5}\sin \dfrac{x}{5}\)