Which of the following is essential for reciprocity theorem to be applicable?

The correct answer is option 3):(Linear and bilateral networks)

Concept:

• Reciprocity Theorem states that In any branch of a network or circuit, the current due to a single source of voltage (V) in the network is equal to the current through that branch in which the source was originally placed when the source is again put in the branch in which the current was originally obtained.
• This theorem is used in the bilateral linear network which consists of bilateral components