Which of the following acids is used in the purification of gold and silver?

Nitric acid

The correct answer is option 2. Nitric acid.

The acid commonly used in the purification of gold and silver is Nitric acid

Nitric acid (HNO₃) is often employed in the process of refining gold and silver. It helps dissolve impurities and other metals that may be present in the raw material, leaving behind purified gold and silver.