What Do Benzene, Arsenic, Cotton Dust, and Vinyl Chloride Have

What do benzene, arsenic, cotton dust, and vinyl chloride have in common?

A) They are identified disease-causing hazards in the workplace.
B) They are suspected of causing diseases in the workplace, but there is no proof.
C) They are disease-causing elements in the workplace that have been eliminated.
D) The Environmental Protection Agency has decreed these substances to be safe in the workplace.
E) They are non-hazardous elements found in numerous workplaces.