What is the term for the arbitrary rule that automatically places the children of a union between members of different socioeconomic groups in the less-privileged group?

The correct term is hypodescent.

Explanation:

The anthropological term hypodescent describes a system where the people of mixed races are automatically put into the category that is considered to be socially inferior.  This is not a system that acknowledges mixed race categories or degrees of racial mixing. In this notion, any racial mixing dilutes the purity of the racial categories. It is a system that tends to discourage racial mixing and intermarriage. We have the example of this kind of system in American history, which is the notion of the one-drop rule. In this framework, one drop of black ancestry made you black by the dominant social standards. This over simplifies the notions of race and it is a very discriminatory part of our history that has perpetrated systemic racism.  

this statement is true.

forests are public goods, available for everybody. when usage of such a good becomes interesting for consumers and its usage increases, there can be a risk of overexploitation. it is a non rival good therefore, if one person consumes the good it does not reduce the availability for subsequent consumers.

these caracteristics require the establishment of measures in order to prevent the destruction of a commonly owned space, for example, to restrict the amount of people that have access to the same time.

a. he allowed the people he conquered to keep their customs and religions.

he captured babylon and freed the jewish people to return to judah.