Dr.Pine is testing a new drug and has a placebo-control group.When he provides the drugs to patients and when he interviews them about side effects,he never knows whether the patient got the drug or the placebo.What is the most likely reason that Dr.Pine chose this type of research design

A)  It reduces the impact of experimenter bias. 
B)  It prevents the halo effect. 
C)  It minimizes the possibility of self-report bias. 
D)  It ensures that the sample is not biased.

Experimenter Bias

A situation where the researcher's expectations or preferences inadvertently influence the participants of an experiment or the interpretation of its results.

Placebo-control Group

In a clinical trial, this is a group of subjects who receive an inactive substance or treatment as a means to control for the placebo effect in the experimental outcomes.

Side Effects

Unintended or secondary effects that can occur as a result of taking medication or undergoing a specific treatment.