Which of the following is false about Longitudinal studies?

Longitudinal studies Longitudinal studies are defined as studies having a direction. Longitudinal studies : Helps us study natural history of a disease. Helps in identification of risk factors of a disease. Helps in find out rate of occurrence of new cases of a diseases. Difficult to organize and more time consuming. Includes 1. Coho study :Forward (prospective) direction; 2 . Case control study :Backward (retrospective) direction. Veical study/ Non-longitudinal study : Include cross-sectional study aka snapshot/ prevalence study , Ecological study aka co-relational study.