In poor inner-city neighborhoods, children sometimes eat paint that is flaking off walls. This can sometimes lead to intellectual developmental disorder due to: A. microcephaly. B. encephalitis. C. lead poisoning. D. meningitis.

What link in the chain of transmission is described in the paragraph? sarah has been eating and sleeping poorly. she was just diagnosed with pneumonia. tests showed the illness was caused by streptococcus pneumoniae. in the chain of transmission, sarah is the (blank) , and streptococcus pneumonia is the (blank).