Asociologist studies children at a day care center. she must get approval from an ethics board because children are a population.

Protected

Explanation:

Protected population is group of people who are protected through various measures of regulation in special way in terms of sociology.This population is considered as vulnerable and thus it is critical situation to include this category in research process as they can be forced for research benefit.This process consist of children, pregnant women ,prisoners etc.

According to the question, for including children in sociological research , sociologist must taker permission from ethic board department as children are considered under protected population.

well, there are a lot of places we get information about earth from. like science classes, websites, books, newspapers, etc.