Answer:
c. More similar to their biological parents than to their adoptive parents.
Step-by-step explanation:
In personality studies, especially in the case of adopted children, the issue of who influences the child more is interesting. The nature vs. nurture state of a child can help determine the nature of a child.
Many researchers have studied the personality of a child, whether the adopted children take after their adoptive parents or their biological parents And it's found that despite never meeting their biological parents, adopted children still exhibit personality traits similar to their biological parents more than that of their adoptive parents. This means that in terms of outgoingness, people who have been adopted will be more similar to their biological parents than their adoptive ones.
Thus, the correct answer is option c.