Final answer:
A) A method to monitor occurrences of public health problems. Public health surveillance is a method to monitor public health problems, supported by the collection and analysis of health data by epidemiologists and health agencies, like the CDC's National Notifiable Disease Surveillance System (NNDSS).
Step-by-step explanation:
Public health surveillance can be primarily described as A) A method to monitor occurrences of public health problems. This involves the systematic collection, analysis, interpretation, and dissemination of health data to help guide public health decision making and action. Surveillance is essential for the planning, implementation, and evaluation of public health practice. It is closely aligned with the work of epidemiologists, who collect data about diseases, their incidence, and spread in a population, and design public health policies to reduce the incidence of diseases or to prevent their spread.
Health agencies obtain data about the incidence of diseases of public health importance through various means, such as clinical records, patient interviews, and the National Notifiable Disease Surveillance System (NNDSS), where physicians are legally required to submit reports on cases of notifiable diseases.