The correct option is E Both assertion and reason are true but reason is not the correct explanation of assertion.
Analysing assertion
Hydrometallurgy involves dissolving the ore in a suitable reagent (like water, dilute acids or sodium cyanide solution) followed by precipitation by a more electropositive metal.
So, it is used for extraction of less electropositive metals like copper, silver, gold.
So, the assertion is correct.
Analysing reason
Copper is extracted by hydrometallurgy.
So, reason is also correct but it is not the explanation of assertion.
Both assertion and reason are true and reason is not the correct explanation of assertion.