The correct option is A Acidic
Non-metals on reaction with oxygen gas give rise to non-metallic oxides. These non-metallic oxides on reaction with H2O give acidic substance. For example, sulphur is a nonmetal. It forms SO2 and SO3 and forms H2SO3 and H2SO4 on reaction with water. On a pH scale, acids always have a value which is less than 7.