Answer:
(a) This is an experiment.
Step-by-step explanation:
The researchers establish an intervention and examine the effects in either of the two conditions. Hence, this is an experimental study. Also, it includes a control group as well as a treatment group. The control group in the given experiment is the firefly colony which is exposed to continuous light whereas, the treatment group is the firefly colony which is exposed to normal darkness and daylight conditions.
The ratio level of measurement is being used in the given experiment because the study counted the number of live fireflies.