What Is True About the Discipline of Epidemiology? Select All

What is true about the discipline of epidemiology? Select all that apply.

A) Epidemiology is the study of the occurrence of health-related events and their determinants in human populations.
B) The objective of epidemiology is to develop effective methods of disease prevention that act directly on causal agents, factors, or determinants.
C) The goal of epidemiology is to discover facts essential or contributory to the occurrence of those affected by the disease under investigation.
D) The importance of epidemiological research is the great impact that disease and injury have on society.