Plutonium is a very toxic element; also is a radioactive element.
Iron is the least poisonous to humans among plutonium, lead, and iron. Iron is an essential nutrient for the body and is required for making red blood cells, while lead can cause various health issues even in small amounts, and plutonium is a radioactive element that can be extremely harmful if ingested or inhaled.
Plutonium, lead, and mercury are all heavy metals. If you knew nothing but that, you should be able to guess that the correct answer is iron. (It might also help to try the various elements in the phrase "Fortified with ____!", and see which of them sounds most familiar from the labels on vitamins or cereals.)
No !!
No, pigs are not poisonous to humans.
Bracken ferns are not poisonous to humans but they are poisonous to animals.
Fortunately, no !
only some fish are poisonous to humans
Snakes are poisonous to humans but not to Meerkats.
No, pure water is not poisonous to humans.
Cedar is not poisonous to humans or animals.
An insignificant amount of plutonium exists in nature. Mostly, plutonium is obtained from nuclear reactions caused by humans.
Fantasy. Plutonium kills humans.