Answer:
b. cross-sectional study
Step-by-step explanation:
A cross-sectional study which is also known as cross-sectional analysis, transverse study or prevalence study. Cross-sectional studies are observational in nature which means this type of research observes the characteristics that exist in a population and do not try to manipulate variables therefore is not done to determine cause-and-effect relationships between different variables. This type of study is done at a specific point in time.