Which of the Following Is a Characteristic of Heavy Metals

Which of the following is a characteristic of heavy metals in the U.S. food supply?

A) Virtually all fish contain trace amounts of mercury.
B) Mercury contamination of fish is most severe in tuna.
C) Toxicity is most severe in the elderly population group.
D) Contamination is usually greater in farm-raised fish than in ocean fish.
E) Older fish are generally safer than younger fish, since they have had more time to excrete the mercury.