In an electrolyte solution, current is maintained by the flow of:
A) Electrons only
B) Negative ions only
C) Positive ions only
D) Negative and positive ions both

Hint-Electrolysis is the process in which the ions are produced when the current is passed through the chemical solution. The chemical solution is called the electrolyte solution. There are cathode and anode dipped inside the solution causing the current to flow in the solution. The current flowing in this process is direct current.

Complete step by step answer:
(i) When the current flows in the electrolytic solution, the current causes the ions to produce at the cathode and anode. The negative ions are released from the cathode and the positive ions are released from the anode. This is due to the oxidation and reduction at the cathode and anode respectively.

(ii) The negative ions reach the anode and the positive ions reach the cathode. These released positive and negative ions get neutralised at the cathode and anode respectively. And the solution remains neutral. The flow of both positive and negative ions causes the current to flow in the electrolytic solution.

Hence the correct option is D.

Additional information:
(i) The cells work under the process of electrolysis. They are primary cells and secondary cells.
(ii) Both primary and secondary cells are built by the process called electrolysis. The difference between these two cells is that the primary cell can be used for only one time. But secondary cells can be used multiple by passing electric current to pass to it.

Note:
The minimum potential required for the production of ions in the electrolytic solution is called electrode potential. The electrolysis process is used in the metallurgy for the preparation of compounds in it. The amount of substance that undergoes in the reduction and oxidation process depends upon the current passing through the electrolytic solution. This is proposed by Faraday in his first law of electrolysis.