The pH of an aqueous sodium fluoride (NaF) solution is ________ because ________ A.above 7; fluoride is a weak base. B. 7; sodium fluoride is a simple salt. C.below 7; fluoride reacts with water to make hydrofluoric acid. D.about 7; fluoride is a weak base but produces hydrofluoric acid, and these two neutralize one another. E.0; sodium fluoride is a salt, not an acid or a base.