The Graph Shown Indicates the Incidence of Whooping Cough in the United

The graph shown indicates the incidence of whooping cough in the United States.What information can you determine from this graph?

A) Approximately 40,000 individuals were infected with whooping cough in 2007.
B) The incidence of whooping cough in infants under one year of age in 2013 was higher than the incidence in 2012.
C) Vaccination against whooping cough has become less effective in infants under the age of one year over time.
D) The incidence of whooping cough declined dramatically between 2005 and 2007.