Lilly's 12-Year-Old Son Used to Get Out of Bed Easily

Multiple Choice

Lilly's 12-year-old son used to get out of bed easily and early on school days, but lately he has been hard to wake. While reading a parenting book, Lilly came across the theory of "delayed phase of preference," in which sleep patterns shift when young people start to go through puberty. In this example, a theory helped Lilly _____.

A) design an experiment
B) change her own behavior
C) generate a discovery
D) gain practical guidance