The primary purpose of double blinding in a randomized controlled trial is to:
group of answer choices
a) achieve comparability of treated
b) untreated subjects avoid observer
c) subject bias make it more ethical reduce the effects of sampling variation

C. Avoid observer and subject bias

Explanation:

Observer and subject bias refers to the pre-conception that the researcher or the subjects have about the outcome of the research before conducting the research itself.

In a  randomized controlled trial , we divided our research subjects into different groups randomly. We need to disregard any grouping with specific characteristics.

Without any similar characteristics, we eliminate any room or reasons for both the subjects and the observer to make any initial judgement. This will increase the likelihood of fair assessment.

i think it is the third one.

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