Correct Answer - Option 4 : neither current source nor emf source
To answer this one should have understanding of active and passive elements
Passive elements:
Components incapable of controlling current by means of another electrical signal are called passive components. Ex. R, L, C diodes
Active elements
It is any type of circuit component with ability to control electron flow.
Ex. Transistor, SCR, Triac etc.
Hence, A passive network does not contain any voltage or current source.