What aspect of the germ theory of disease has influenced the behavior of most of the individuals in the picture below?

A)Coughing in a public place is socially unacceptable.
B)Disease-causing pathogens are communicable; they can spread from an infected individual to an uninfected individual.
C)Medications like antibiotics are a selection mechanism that ultimately strengthens the disease.
D)The pathogens that cause disease are too small to be seen without a microscope.