Concept:Baking hardens clay by removing water and fusing particles, making pottery strong and durable.Explanation:Pottery is shaped from moist clay. To make it strong and permanent, it must be heated in a kiln or fire – this is called baking. During baking, water evaporates and clay particles fuse together, creating a hard, waterproof structure. Without baking, dried clay remains fragile and crumbles easily. Smelting is used to extract metals from ores, not for clay. Roasting is for cooking food or processing ores. Burning is a general combustion process that does not give the controlled hardening needed for pottery. Therefore, the correct method is baking.Answer:A. by baking