I’m not an expert but I’d say B
It’s because unlike twins the regular siblings aren’t born on the same date or a couple minutes apart, but rather a couple years old or younger.
A cybernetic hand, that is powered by one's nerve impulses.
C is the most likely answer to this question.
<span>One group is given a larger dosage than is typically prescribed.
A second group is given a smaller dosage than is typically prescribed
Then results of the groups are compared to each other.
The thing that is missing in this experimental design is a third group who are tested with the typical dosage.</span>
