Respuesta :
Answer:
D. Testing the effectiveness of a hair product allowing one group to use it and comparing results against a control group.
Step-by-step explanation:
By definition, survey is a method of gathering information from a sample of people, traditionally with the intention of generalizing the results to a larger population.
From this definition it shows that during survey a group of entity (sample) representing the entirety (population) will be examine.
Therefore option
D. Testing the effectiveness of a hair product allowing one group to use it and comparing results against a control group.
From this one group is examine but generalizing the results to a larger population.