Correct option is D
In given figure this is a type of rat-tail Joint.
Rat tail Joint- A rat-tail splice also know as a twist splice or a pig-tail splice. It is a very basic electrical splice that can be done with both solid and stranded wire. It is made by taking two or more bare wires and wrapping them together symmetrically around the
common axis of both wires. The bare splice can be insulated with electrical tape or other means.
This common and simple splice is not very mechanically strong. It can be stronger by use of solder.
