Identify the Following as an Experiment or an Observational Study

Identify the following as an experiment or an observational study.
-A researcher wished to assess the importance of exercise in weight-loss programs. The participants in a study were randomly assigned to one of two groups. Over a two-month period, the first group followed a particular
Diet but performed no exercise other than walking. The second group followed the same diet but also
Performed aerobic exercise for one hour each day. At the end of the two months, it was found that the average
Weight loss for the second group was significantly greater than the average weight loss for the first group.

A) Observational study
B) Experiment