Which of the following statements about the development of the germ theory of medicine is correct?
a. Robert Koch was especially noted for his discovery that hand washing techniques and the use of antiseptics greatly reduced infections after surgery.
b. Louis Pasteur's work on treating malaria caused scientists to conclude that animals such as mosquitos could spread malaria.
c. John Snow's efforts to fight cholera in London challenged the miasma theory of medicine and suggested germs caused illness.
d. Joseph Lister's invention of mouthwash led to major improvements in dentistry.