The answer is false since it saves it but does not prevent anything
C.an emotion that is expressed by people in all cultures
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.
Answer:
in controlled experiment an independent variable is systematically manupulated and dependent variable is measured ; any extraneous variables are controlled
