a temporary circuit used for testing purposes is created by using\na a jumper.\nb an electrode.\nc an…

Brief Explanations:

A jumper is a short - length of wire used to create a temporary electrical connection for testing purposes. An electrode is for making electrical contact in a non - temporary connection in electrochemical or other setups. An extension cord is for extending a power connection over a distance, not for creating temporary test circuits. A conductivity tester is for measuring conductivity, not for creating a circuit.

Answer:

A. a jumper