Adouble-blind study is one in which neither the researchers nor the subjects know wether the subject is receiving the real treatment or the placebo. what is the value of this kind of study?
a. neither the subjects nor the researchers can bias the results.
b. the researchers cannot replace the placebo with the the real treatment for their favorite subjects.
c. the subjects are not irritated by the fact that they are not receiving the real treatment.
d. neither the subjects nor the researchers are able to interpret the results.

A. Neither the subjects nor the researchers can bias the results.

Explanation:

As described, a double- blind study is one in which the researcher and his study does not know the person receiving the actual treatment.

Researchers can be bias in their studies as they seek to establish and fine tune results in the way the best favors them. A double-blind study helps to bridge this gap to prevent bias that might be introduced into an experimental set up or while interpreting results.

The correct answer is A. Neither the subjects nor the researchers can bias the results.

Explanation:

In regular research studies, the subjects or researchers can manipulate the results or bias these, this in the case of the researches occurs when they manipulate the results of the study based on their interests, prejudices, etc. Also, subjects can manipulate consciously or unconsciously the results if they know whether they are in the group with the treatment or the placebo. However, if neither the subjects nor the researchers know about sho is receiving the treatment of the placebo as it occurs in a double-blind study, they will be more objective and would not manipulate the study or bias the results. Thus, one value of this kind of study is "Neither the subjects nor the researchers can bias the results".

it's c. elements are placed in rows based on how may valencies electrons have.