A.\(\sqrt {{R^2} + {{\left( {\omega C} \right)}^2}} \)
B.\(\sqrt {{R^2} - {{\left( {\omega C} \right)}^2}} \)
C.\(\sqrt {{R^2} + {{\left( {\frac{1}{{\omega C}}} \right)}^2}} \)
D.\(\sqrt {{R^2} - {{\left( {\frac{1}{{\omega C}}} \right)}^2}} \)