Which of the following is a resonant or tuned circuit?

A resonant or tuned circuit is created by combining an inductor (coil) and a capacitor, either wired in series or in parallel. These two components store and release energy in opposing ways; the capacitor stores energy in an electric field, while the inductor stores it in a magnetic field. At one specific frequency, their AC resistances (reactances) cancel each other out, allowing the circuit to 'resonate.' This precise resonant property is what allows radios to tune into a single specific frequency and reject others.