The following species cannot produce salt on reaction with acid.

Explanation

The correct answer is Option B: Metals. Not all metals react with acids to form salts. For instance, noble metals like gold and platinum do not form salts when they react with acids due to their lack of reactivity. Option A, carbonates, reliably form salts when reacting with acids, alongside water and carbon dioxide. Option C, non-metal oxides, generally react with bases rather than acids to form salts. Option D, metal hydroxides, undergo neutralization reactions with acids to produce salts and water.