A researcher is adminstering drugs to mice as part of an approved study and is selecting the drug or placebo from containers labeled only A, B & C. The mice have been randomly assigned to either one of two treatment groups or the control group and the researcher is following a printed chart that links each animal to their treatment container (A, B or C). The three treatments are all indistinguishable to the researcher (visually and otherwise) and the researcher is unaware of what is in container A, B or C. What kind of experiment is this? (A) double-blind experiment (B) clinical trial (C) single-blind experiment (D) fully-blind experiment

The answer is A) double-blind experiment

Explanation:

Blinded studies are a useful way to avoid bias in the results of a study. In a randomized double-blind study, the subjects, in this case the mice, are randomly assigned to a group of treatment. Double-blind refers to the fact that neither the researcher nor the subjects of study know which group is receiving a specific treatment. Single-blind is a study in which the physician or researcher is aware of the treatment that is being given but the subjects of study are not. Clinical trials are done in human patients, not in animals, those are called preclinical trials. The common terms for blinded studies are: unblinded, single-blinded, double-blinded and triple-blinded not fully-blinded.