Question

The German physician Robert Koch provided evidence to support the germ theory of infectious disease. Koch isolated bacteria from a cow with anthrax then injected the bacteria into a healthy mouse. To support germ theory, what must have happened to the healthy mouse?
A: it became sick.
B: it spread smallpox.
C: it produced antibiotics.
D: it became immune to viral infections.​

Answer 1

A. They became sick. Hence, the Koch hypothesis.