The correct answer is: B. Ex-post facto research.
Ex-post facto research is a type of research in which the investigator attempts to trace an effect by examining the relationship between two or more variables after the fact. This type of research is often used in the social sciences, where it can be difficult to conduct experimental research.
For example, an investigator might conduct an ex-post facto study to examine the relationship between smoking and lung cancer. The investigator would collect data on a group of people who have lung cancer and a group of people who do not have lung cancer. The investigator would then compare the two groups to see if there is a difference in the number of people who smoke.
Ex-post facto research can be a useful tool for understanding the relationship between two or more variables. However, it is important to note that this type of research cannot prove cause and effect. This is because the investigator cannot control for all of the variables that might affect the relationship between the two variables being studied.
Survey research is a type of research in which the investigator collects data from a sample of people by asking them questions. This type of research is often used to understand the attitudes, beliefs, and behaviors of a population.
Historical research is a type of research in which the investigator examines historical documents to understand the past. This type of research is often used to understand the causes of events, the development of ideas, and the lives of people.
Summative research is a type of research in which the investigator assesses the effectiveness of a program or intervention. This type of research is often used to determine whether a program or intervention is meeting its goals.