Consider the following properties of a particular network theorem:
1. The theorem is not concerned with type of elements.
2. The theorem is only based on the two Kirchhoff's laws.
3. The reference directions of the branch voltages and currents are arbitrary except that they have to satisfy Kirchhoff's laws.
Which one of the following theorems has the above characteristics?

A. Thevenin's theorem

B. Norton's theorem

C. Tellegen's theorem

D. Superposition theorem

Answer: Option C