The term "half-life" is used to describe the amount of time it takes for 50 percent of a substance’s original radioactivity to decay. Radioactive substances with a long half-life must be stored for longer periods of time, but the radiation during any given period of that time is less intense than for radioactive substances with a short half-life. Which of the following is true of the relationship between half-life and human health?

Elements with a long half-life are dangerous in the long term.
Elements with a short half-life are not dangerous in the long term.
Elements with a long half-life are very dangerous in the short term.
Elements with a long half-life and elements with a short half-life are not dangerous in the long term.
Elements with a long half-life and elements with a short half-life are equally dangerous in the short term.