Answer:
Zach and Tuila are demonstrating generativity.
Step-by-step explanation:
Generativity, a concept first used by Erik Erikson, it's a care or concern for guiding the next generation. In the exercise, Zach and Tuila are parents that have a care for their children: even if they had to change their lifestyles, both economical and daily, they do it happily given that they know that their children will be taken care off. Therefore, they are demonstrating generativity.