多选题 When the void keyword is used, which of the following statements are true? (Choose all that apply.) A. A return statement with a value following it must be used. B. A return statement with a value following it can optionally be used. C. A return statement with a value following it should never be used. D. A return statement by itself must be used. E. A return statement by itself can optionally be used. F. A return statement by itself should never be used. G. A return statement must be omitted. H. A return statement can optionally be omitted. I. A return statement should never be omitted.