C is the best answer.

In the third paragraph, the author cites Zelizer’s contention that the new view of childhood that developed in nineteenth-century America was due in part to “the development of the companionate family (a family in which members were united by explicit bonds of love rather than duty)”(lines 54-58). From this it can be inferred that the emotional bonds between family members became increasingly important during this period. There are no information in the passage to support the other answer choices.