Sodium
Carbon
Bromine
Iron
The correct option is A Sodium
Metal oxides are basic in nature. Hence, answer could be options A and D. But most metal oxides are insoluble in water and only some of these dissolve in water to form alkalis. Sodium oxide and potassium oxide dissolve in water to produce alkalis as follows –
Na₂O(s) + H₂O(l) → 2NaOH(aq)
So, the correct option is A