Assertion: In the presentation EFe3+/Fe2+ and ECu2+/CuFe3+/Fe2+ and Cu2+/Cu are redox couples.

Reason: A redox couple is the combination of the oxidised and reduced forms of a substance involved in an oxidation or reduction half cell.

1. Both the assertion and the reason are true and the reason is the correct explanation of the assertion.
2. Both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
3. The assertion is true but the reason is false.
4. The assertion is false but the reason is true.
Hint: Oxidation-reduction reaction, also called redox reaction
A redox couple is defined as pair of compounds or elements having together the oxidised and reduced forms of it and taking part in an oxidation or reduction half-reaction. So,  and  are redox couples.