{Using Impedance Formula}
\[ Z = \sqrt{(X_L - X_C)^2 + R^2} \] Since \( X_L = X_C \), \[ Z = \sqrt{(R - R)^2 + R^2} = \sqrt{0 + R^2} = R \] Thus, the correct answer is \( R \).
Find the average value of the current shown graphically from \( t = 0 \) to \( t = 2 \) s.