Answer:
A. They were part of the control group
Explanation:
In a scientific experiment, the CONTROL GROUP as opposed to the experimental group is the group that does not receive the experimental treatment. This acts as a standard for comparison.
In this question, the EXPERIMENTAL VACCINE is the experimental treatment or independent variable that was added. The five animal test subjects that was injected with this vaccine are called the EXPERIMENTAL GROUP while the other five test subjects that were rather injected with a PLACEBO are called CONTROL GROUPS.
That's a hard one but I would go with A unwanted transpitation. Hope that helped :)
Answer:Latitude and ocean currents
<span>Hyracotherium, Mesohippus, Merychippus, Pliohippus, because over time, the number of toes decreased and body size increased is the right answer</span>
