Why Ideal inductors and capacitors have no resistance, so they cannot convert electrical energy into heat. Instead they take energy from the source during part of the AC cycle and store it in a magnetic field (inductor) or an electric field (capacitor), then return that same energy to the source during the next part of the cycle. That back-and-forth flow is called reactive power, measured in VAR, and its net average over a cycle is zero. Only real power, dissipated in resistance, produces heat.
Watch out The choices describing dissipation as heat or dissipation in forming the fields confuse reactive power with real power; only resistance dissipates energy, and building a field stores energy rather than consuming it.
Reactance borrows, resistance burns. Ideal L and C give the energy back.