A case-control study produced this data: Cases: exposed 40, unexposed 20. Controls: exposed 30, unexposed 80. Calculate the odds ratio and recommend the most appropriate public health interpretation.

OR ≈ 0.19; exposure is protective and no action is needed

OR ≈ 5.33; strong association suggests exposure may be an important risk factor and warrants further analytic and possibly intervention efforts

Relative risk = 5.33 which proves causation and mandates immediate mandatory cessation of the exposure for all students

Odds ratio cannot be calculated from a case-control table and therefore no inference can be made