An appropriate summary for the article "A Most Troublesome Element" is the last option - C. Arsenic is a naturally occurring, poisonous element that has threatened the health of humans since the Middle Ages.
It clearly states what the whole article is about.
My PE teacher used to be a professional swimmer, he taught us a lot about official contests rules and stories he experienced, he's one of our favorite teacher.
The energy comes from the food depends on what you eat such as protines and other!
