Provide an Appropriate Response

Provide an appropriate response.
-A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly
Assigns half of a group of overweight persons to a treatment group who are given the herb with instructions as
To use and a planned diet for six weeks. The other half of the group is given the same diet without the herb.
Participants are aware as to which group they belong. A nurse at the nutrition center weighs each subject on
Friday of each week. Identify any problems that are likely to cause confounding.

A) The placebo effect
B) Method of assignment to treatment and control groups
C) Experimenter effect
D) The study is essentially free of confounding sources.