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.
Alcohol abuse? The question is kind of misleading
There are 20 drops in 1 mL.
2L = 40,000 drops
24 hour = 1440 mins
flow rate = 40000/1440
= 28 drops per mins
