Any reported connection between electromagnetic fields, such as those produced by high-tension wires, and cancer is unsubstantiated. The cancer rate of urban residents is at least as high as that of people living in rural areas close to high-tension wires.

Which of the following, if true, would most severely damage the claim above?


Most cancers are caused by interactions between biochemical and environmental factors.

Although in many big cities the electrical system is hidden from view, residents of such cities may be living very close to the underground sub-stations of utilities, which produce strong electromagnetic fields.

Electromagnetic fields are produced not only by high-tension wires but also by ordinary household appliances, such as microwave ovens and refrigerators.

The cancer most often linked with electromagnetic fields is leukemia, which is incurable.

Both big cities and areas near high-tension wires are not free of the myriad number of known cancer-causing agents.