The School Nurse Becomes Aware of a Group of Children

The school nurse becomes aware of a group of children who come to the clinic reporting itching and the presence of round red marks on their skin. The school nurse contacts the health department who initiates protocol for the treatment of bedbugs. Which event likely triggered the health department's action?

A) Syndromic surveillance by the school nurse
B) Medical reports from family healthcare providers
C) On site visits and examinations by public health nurses
D) Identification of skin scrapings sent to a local laboratory