Studies show that families in which both the husband and the wife are working normally tend to be single-child families. It is commonly understood that
such partners prefer to have only one child because of the lack of time on their hands to raise more than one child. However, other studies have shown that in households that have both the husband and wife working but that have more than one child, the partners married each other in their early twenties. Since
majority of the working parents in single-child households marry post the age of thirty-five, it is clear that the real reason such families have only one child is the age of the parents that does not biologically allow them to have more than one child.
In the argument given, the two portions in boldface play which of the following roles?
A. The first is an intermediate conclusion that supports the main conclusion of the argument; the second is used as a support for the position the argument seeks to establish.
B. The first is evidence for a position that the author does not agree with; the second is the main position taken by the argument.
C. The first is an explanation offered for an observation; the second is an observation that is used to support the position taken by the argument.
D. The first is an explanation offered for an observation; the second is that observation.
E. The first is a conclusion that supports the main conclusion of the argument; the second is a belief that too supports the main conclusion of the argument