Metals known to Indus Valley Civilization were:

The correct option is A Gold, copper, silver, bronze but not iron
Gold, copper, silver, bronze metals were known to Indus Valley Civilization but not iron. The Indus valley people or Harappan people not discovered iron. The Indus Valley Civilization was a Bronze Age Civilization extending from what today is northeast Afghanistan to Pakistan and northwest India, it was one of three early Civilization of the Old World. Inhabitants of the ancients Indus river valley developed new techniques in handicraft (carnelian products, seal carving) and metallurgy (copper, bronze, lead, and tin).