The greatest protection against the ability of life on Earth's surface is that the Earth's magnetic field deflects large amounts of charged ions and isolates large amounts of harmful cosmic rays from the atmosphere. Recently, scientists found that the South Atlantic magnetic field began to flip the Earth's magnetic field is being weakened. They have studied the idea that if the Earth's magnetic field were reversed, all living things would be extinct without magnetic protection.
The statement 'When the magnetic field is reversed, life on Earth is exposed to unprotected surfaces, resulting in a major outbreak of skin cancer' best supports the above conclusion.