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.
Normal cells<span> listen to signals from neighboring </span>cells<span> and stop growing when they encroach on nearby tissues (something called contact inhibition.) </span>Cancer cells<span> ignore these </span>cells<span> and invade nearby tissues. Benign (non-</span>cancerous<span>) tumors have a fibrous capsule.</span>
<h2>c) option is correct</h2>
Explanation:
Melanin causes skin pigmentation, lowers the skin's ability to make vitamin D in response to sunlight exposure and some studies show that older adults with darker skin are at high risk of vitamin D deficiency
If there is lighter skin tones of people, it implies that the amount of Vitamin D is more in those people and skin of those people have the ability to process vitamin D from the sun