Answer:
c. Experimental
Step-by-step explanation:
Experimental study or research design: In research, the term "experimental study or research design" is often considered as a standard study design. In the experimental research design, one or more than one dependent variables or subjects are being randomly assigned to distinct treatments, i.e., the "independent variables" are being manipulated by the investigator or researcher and the results of the experiment are generally observed to make a conclusion.
In the question above, the given statement represents the "experimental study design".