Correct Option: C

An early-20th-century form of quackery was the treatment of maladies in a radiotorium. It was a small, sealed room for patients to be exposed to radon for its “medicinal effects”. The carcinogenic nature of radon due to its ionizing radiation became apparent later on. Radon’s molecule-damaging radioactivity has been used to kill cancerous cells. It does not, however, increase the health of healthy cells. In fact, the ionizing radiation causes the formation of free radicals, which results in genetic and other cell damage, resulting in increased rates of illness, including cancer. Exposure to radon, a process known as radiation hormesis, has been suggested to mitigate auto-immune diseases such as arthritis. As a result, in the late 20th century and early 21st century, “health mines” established in Basin, Montana attracted people seeking relief from health problems such as arthritis through limited exposure to radioactive mine water and radon.