Answer:
C
Explanation:
<em>The correct answer would be the group that was given a placebo.</em>
A control group in an experimental study is the group that is subjected to all other conditions except the variable whose effects are being determined during the course of the experiment.
<u>Since the main goal of the research is to evaluate the effectiveness of the HPV vaccine, the difference between the experimental and the control group would be the vaccine.</u> Instead, the control group would be given a placebo - a substance that is designed not to have any effect but looks like the vaccine itself.
<em>Correct option: </em><em>C</em>
The removal of Balanus shows that the realized niche of Chthamalus is smaller than its fundamental niche. <span>These two species of barnacle do not show competitive exclusion.</span>
Some possible scenarios include worldwide temperature change, worldwide disease breakout, environmental change, and lack of resources.
When the change of temperature in a space is measured and can be controlled to get a preferred temperature.