The correct answer is A. Ex post facto research means the research is carried out after the incident.
Ex post facto research is a type of research that is conducted after the event or phenomenon has occurred. This type of research is often used to study the causes of a particular event or to determine the effects of a particular intervention. Ex post facto research can be difficult to conduct, as it is often difficult to control for all of the variables that may have influenced the event or phenomenon being studied. However, ex post facto research can be a valuable tool for understanding the causes of events and the effects of interventions.
The other options are incorrect. Option B is incorrect because ex post facto research is not conducted prior to the incident. Option C is incorrect because ex post facto research is not conducted along with the happening of the incident. Option D is incorrect because ex post facto research is not conducted keeping in mind the possibilities of an incident.