The youngest of Zach and Tuila's three children has just started kindergarten. They have had to change their morning and bedtime routines, child care arrangements, and discipline practices. The family's income has suffered as a result of this shift, yet Zach and Tuila are happy to make these changes for their children.
These changes reflect the fact that _____.

A) Zach and Tuila do not know enough about parenting
B) their children must be especially difficult
C) Zach and Tuila are trying too hard to please their children
D) Zach and Tuila are demonstrating generativity