Answer:
<em><u>A. Neither the subjects nor the researchers can bias the results.</u></em>
Explanation:
As described, a double- blind study is one in which the researcher and his study does not know the person receiving the actual treatment.
Researchers can be bias in their studies as they seek to establish and fine tune results in the way the best favors them. A double-blind study helps to bridge this gap to prevent bias that might be introduced into an experimental set up or while interpreting results.
sand dunes form from wind
Answer:
c
Cause at the bottom it is cold and up top is warmer
Depth, flow, temperature, and chemistry of overlying water
