The question seems complicated but can be easily simplified if one keeps a track
of all the connections and identify the equipotential points.
Here 2, 4 and 5 are equipotential. Also 3, 6 and 8 are equipotential.
Representing the above points in a simple linear potential diagram results in the
following picture. Here, each connection corresponds to a resistance R
This is a very powerful technique. Student is expected to be thorough with its use.
Ans : (C)