Answer
The current curve shifts rightward and the amplitude of that curve increases.
Work Step by Step
The emf curve lags behind the current curve.
Therefore, $X_C \gt X_L$
Note that $X_C = \frac{1}{\omega_d~C}$
If we slightly increase $C$, then $X_C$ decreases, and $X_C$ gets closer to $X_L$, which is closer to resonance.
Therefore, the current curve gets closer to the emf curve, and the amplitude of the current curve increases.
The current curve shifts rightward and the amplitude of that curve increases.
