An example of a(n) double-blind research study would be where an experiment was conducted on caffeine-induced stress when neither the class researchers nor the test subjects knew who received caffeine and who did not until after the study was finished.
<h3>What is double-blind research study?</h3>
A double-blind study is one in which neither the participants nor the researchers are aware of which group is getting the treatment.
However, it also prohibits researchers from unintentionally disclosing information about the experiment.
This type of study is particularly helpful in avoiding biased reports that are likely the result of placebo effects.
Imagine, for instance, that researchers are looking into the effects of a novel medication.
The participants in a double-blind study would not be aware of who was receiving the real medication and who was receiving a placebo, and neither would the researchers who contact with them.
It's a hard choice between A and D, but I think A leans more closely to the answer. The whole point of the Articles of Confederation was trying to make a unifying Union while keeping the states' independence.
