GATE EC 2016 Set 1 Q31 — Op-amp Circuits

A network consisting of a finite number of linear resistor (R), inductor (L), and capacitor (C) elements, connected all in series or all in parallel, is excited with a source of the form

$$\sum_{k=1}^{3} a_k\cos(k\omega_0t) ,\text{where } \thinspace a_k\neq 0, \omega_0\neq0$$

The source has nonzero impedance. Which one of the following is a possible form of the output measured across a resistor in the network?