The invention of which diagnostic instrument confirmed diseases were caused by microorganisms and not angry Gods?

• A. Stethoscope
• B. X-ray
• C. Microscope
• D. Thermometer

Answer: (C)

Seeing is believing: the microscope lets us directly observe the tiny living organisms that can cause disease. By visualizing bacteria and other microbes, scientists obtained concrete evidence that illnesses can arise from these organisms rather than from supernatural forces. This direct observation helped shift belief from gods or fate to germ theory, paving the way for techniques like sterilization, vaccination, and antibiotics. The other tools diagnose or reveal aspects of the body’s function or structure—sound in the chest, internal anatomy, or temperature—without showing the microbes themselves, so they don’t provide the same proof that diseases originate from microorganisms.