The correct answer is A. NaOH.
An Edison cell is a type of primary cell battery that uses a zinc anode, a copper cathode, and a sodium hydroxide electrolyte. The cell was invented by Thomas Edison in 1899 and was used in early electric lamps.
The zinc anode is the negative electrode of the cell. It is made of zinc metal and is placed in a solution of sodium hydroxide. The copper cathode is the positive electrode of the cell. It is made of copper metal and is placed in a solution of sodium hydroxide.
When the cell is in use, the zinc anode dissolves in the sodium hydroxide solution, forming zinc ions. The copper cathode is reduced by the zinc ions, forming copper metal. The electrons released by the zinc anode flow through the external circuit, powering the load.
The sodium hydroxide electrolyte is a liquid that conducts electricity. It is made by dissolving sodium hydroxide in water. The sodium hydroxide ions in the electrolyte carry the current between the anode and cathode.
The other options are incorrect because they are not electrolytes that are used in Edison cells.