A nutrition scientist designs a study in which he assigns 100 people to the treatment group and 100 people to the control group. Although the scientist knows each person's group assignment, the subjects are not aware of their group placement. This is an example of .a. double-blind study
b. uncontrolled study
c. single-blind study
d. biased study

Option C, single-blind study

Explanation:

In a single blind study, the researcher is aware of the experimental group in which the subject is placed. However, the subject is unaware of its placement. Such kinds of experiments are conducted to reduce the risk of errors or variation in participant’s response, if they come to know the group type in which they are placed.  

In a double blind study both the researcher and the subject of the experiment are unaware of the groups in which the subject is placed while conducting the experiment

Hence, option C is correct

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.