Which of the following causes mad cow disease?

Explanation

Mad Cow Disease (Bovine Spongiform Encephalopathy, BSE) is a fatal neurodegenerative disorder in cattle caused by prions-misfolded proteins that damage the brain. It spreads mainly through contaminated feed containing infected nervous tissue. In cattle, symptoms include loss of coordination, behavioral changes, difficulty walking, weight loss, and death. In humans (variant Creutzfeldt-Jakob disease), it causes memory loss, confusion, personality changes, muscle stiffness, and coordination problems, eventually leading to coma and death. Prevention relies on banning contaminated animal feed, strict meat inspection, and culling infected animals.