In developing his theory of cognitive development, Schaie focused on changes in the way adults information rather than looking at changes in the way adults information.

The correct answer is use; understand

The theoretical model planted by Schaie is based on the fulfillment of motivational objectives over the life cycle that answered the three questions previously explained: what do I need to know? How do you practice ?; Why is that what? Under these three premises, Shaie proposes 7 stages of cognitive development.

i would say b. research typically uses a variety of sources

chavez's example shows that nonviolent protest can work well. it shows that one nonviolent man can stop a mob, which proves chavez's point and persuades people to protest nonviolently.