A Pharmaceutical Company Has Developed a Medication Which They Believe

A pharmaceutical company has developed a medication which they believe will help to reduce the pain of arthritis.They would like to test the medication at two different dosage levels.They design an experiment as follows to test the medication.They will obtain a group of volunteers who suffer from arthritis.A doctor from the pharmaceutical company will evaluate each patient's condition at the start of the experiment.Volunteers will be randomly assigned to one of three groups.Each day for the duration of the experiment,patients in group 1 will receive a low dose of the medication,patients in group 2 will receive a higher dose of the medication,and patients in group 3 will receive a placebo.After a suitable amount of time (two months,for example) ,the same doctor will evaluate each patient's progress.Based on the amount of inflammation and the patient's report on the amount of pain,the doctor will give each patient a numerical score to represent their improvement.The amount of improvement for the three groups will then be compared.The researchers will have the technicians administering the medication blinded to whether patients receive a low dose,a high dose,or a placebo.Identify the most serious flaw in this experiment.

A) There could be lurking variables.
B) The volunteers should have been randomly selected.
C) The doctor should choose the best treatment for each patient,instead of allowing volunteers to be assigned at random to a treatment.
D) The experiment is only single blind.The doctor evaluating the patients' progress is not blind to which treatment patients received.
E) There is no blocking.