The Nurse Is Appraising New Epidemiologic Research Concerning the Reported

The nurse is appraising new epidemiologic research concerning the reported cases of measles over the past 5 years. Which is the best explanation for the nurse to apply to "risk factor" when analyzing this research?

A) Course of a disease or condition from the onset to resolution
B) Primary measurement used to describe either the occurrence or the existence of a specific state of health or illness
C) Probability or likelihood that a disease or illness will occur in a group of people who presently do not have the problem
D) Characteristic or event that has been shown to increase the probability that a specific disease or illness will develop