Are Patches More Effective Than Oral Medication in Helping Individuals

Are patches more effective than oral medication in helping individuals stop smoking? Two researchers randomly assigned 22 people to one of the two treatment groups (11 people were assigned to each group) . The subjects were monitored for six weeks, during which they received treatment every day-a new patch for subjects in the first group and a single pill for subjects in the second group. The researchers reported that subjects wearing the patches were less likely to quit smoking, although the difference was not statistically significant. Which type of study is this?

A) Convenience sample
B) Observational study
C) Experiment, but not a double-blind experiment
D) Double-blind experiment