A.\(\int {f\left( x \right)dx}  =  - \dfrac{{\cos 5x}}{5} + C\)
B.\(\int {f\left( x \right)dx}  = \cos 5x + C\)
C.\(\int {f\left( x \right)dx}  = 5\cos 5x + C\)
D.\(\int {f\left( x \right)dx}  = \dfrac{{\cos 5x}}{5} + C\)