Which of the following statements is the most accurate definition?

a.Passive surveillance is an observational investigation, usually descriptive, in which information is systematically collected.

b.Sentinel surveillance is a type of surveillance based on selected population samples chosen to represent the relevant experience of particular groups.

c.Passive surveillance provides stimulus to health care providers in the form of individual feedback or other incentives.

d.Active surveillance often gathers disease data from all potential reporting health care providers.

e.Active surveillance is continuous analysis, interpretation, and feedback of systematically collected data, generally using methods distinguished by their practicality, uniformity, and rapidity rather than by accuracy or completeness.