Answer: The answer is A: selenium
Chinese scientists demonstrated that selenium supplements could prevent Keshan disease.
Explanation: Keshan disease is a type of disease caused by absence of selenium in an individual’s body. Keshan disease is a fatal form of disease of the heart muscle.
Selenium supplements are essential nutrients for humans. The absence of selenium supplements in human body can make the eyes, immune system, joint and so on to suffer. Small amount is needed in the body for good health.