Explain whether an experiment or an observational study would be more appropriate to investigate whether women are more likely than men to suffer from anxiety. O Observational study; gender cannot be assigned as a treatment. 
O Experiment; an observational study would take too long. 
O Observational study; it is unethical to subject study participants to anxiety over a long period of time. 
O Observational study; it would be easier to control for lurking variables such as number of hours worked per week. 
O Experiment; it would be easier to control for lurking variables such as number of hours worked per week