Which of the following statements about radioisotopes is true?

A) A radioisotope with a short half -life emits more radiation than the same mass of a radioisotope with a long half life.
B) Radioisotopes with long half-lives are considered dangerous because they may persist for millions of years.
C) Some radioactive elements are accumulated in food.
D) Radioactive radon gas is naturally occurring and presents a potential danger to occupants of homes with basements.
E) All of the above