What Did the Research by Adachi and Colleagues (2009) Show

What did the research by Adachi and colleagues (2009) show in relation to the value of educating parents about the sleep of their young children?

A) Children whose parents received education about sleep experienced few sleep problems.
B) Children need to be at least six to show benefits of sleep education.
C) Education can be effective if multiple follow-ups occur to ensure the parents retain the information.
D) There was no real effect because the sleep-deprived parents were unable to retain the information.