Which of the following components should be added to a capacitor to increase the capacitance?

To increase the total capacitance in a circuit, you must add another capacitor in parallel. When capacitors are wired in parallel, their effective plate areas add together, allowing them to store more total charge for a given voltage. Therefore, parallel capacitance values simply sum together (C_total = C1 + C2). Adding a capacitor in series will actually decrease the overall capacitance, because series capacitors follow the reciprocal formula. Adding an inductor, whether in series or parallel, introduces inductance into the circuit rather than increasing its capacitance, altering its resonant properties entirely.