Final answer:
Infected prions cause disease by inducing the abnormal folding of normal prion proteins in the brain, leading to a chain reaction that results in brain damage and fatal neurodegenerative diseases.
Step-by-step explanation:
The statement that best explains how infected prions cause disease is c) They induce abnormal folding of normal proteins in the brain. Prions are infectious agents composed entirely of protein material that can fold in multiple, structurally distinct ways, at least one of which is transmissible to other prion proteins, leading to a chain reaction that disrupts the structure of normal protein within the brain. This abnormal folding of the prion proteins, notably from the normal form (PrPC) to the disease-causing form (PrPSC), leads to progressive brain damage and the development of transmissible spongiform encephalopathies such as Mad Cow Disease and Creutzfeldt-Jakob Disease. Prion diseases are marked by rapid mental and physical deterioration, and unfortunately, no cure exists for these conditions.