Which of these is most likely to lead someone to decrease his or her level of physical activity? A. Advertising for exercise apps
B. Internet articles with information about healthful lifestyles
C. Advertising for community events that promote an active lifestyle
D. Marketing campaigns for online video game.

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).