Answer:
Experimental but not double-blinded study
Explanation:
The type of study being described is an Experimental but not double-blinded study. That is because it is a study that has a control group, dependent variable, and an independent variable all used in order to acquire specifically targetted data from the results that are derived from the experiment itself. Also since the scientists/researchers know exactly which lab sections are getting the extra review material (independent variable), then that makes this a non-double-blinded study.