Choose all that is true about the different study designs we learned in class compared to experiments.

a. The generalizability of the study results depend on the effect measure that is calculated.
b. Ecological and quasi-experimental studies both measure the exposure on the group.
c. The key difference between experimental studies and prospective cohort studies is the random assignment of individuals to exposure or nonexposed groups.
d. RCT are also known as community trials.
e. Observational analytical studies are single-blinded because the participants don't know what exposure is the focus of the study.