Answer: d. double-blind
Explanation:
A double blind study can be define as the study in which both the researcher and participant do not know which participant is receiving a particular treatment. This method is useful as it prevents the bias in the results of the experiment.
The given situation is the example of double-blind study. Here, the participants as well as the researcher do not know which group of subject are receiving bacteria in the yogurt and which group is not receiving.
B.Workplace air quality C.UV <span>exposure</span>
Natural foods contain substances that protect the body against diseases, and are often more satisfying than supplements.<span>
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In a discussion of 2 people for sure there are certain ideas being shared by both parties. TO make sure that the discussion they shared are positive and rewarding, they must learn to listen to each other's ideas and sharing, they must also learn to acknowledge and always meet in the middle.