Public Health Began to Improve in the Early Nineteenth Century

Public health began to improve in the early nineteenth century because of all of the following except

A) Edward Jenner's development of the smallpox vaccine
B) The "miasma" theory of disease triumphing among both doctors and the public
C) The success of Edwin Chadwick's campaign for improved public sanitation
D) Doctors beginning to do thorough physical examination of patients instead of relying on the patients' . description of their symptoms