<prompt> Case series repo is a type of ?Analytic studyExperimental studyObservational studyIntervention study  <response>: Ans. is c i.e., Observational study A Observational studiesDescriptive studies : Case repos, case series.Analytic studies : Case-control case-reference, Coho follow-up, Ecological correlational, Cross-sectional.B Experimentalintervention studiesRandomized controlled trialsclinical trials.Community trials.Field trials. Animal studies. 