The Text Suggests That Both Key Variables and the Type

The text suggests that both key variables and the type of participants should be mentioned in the article title. Which one of the following titles meets both criteria?

A) The test of attribution theory on middle-schoolers in rural Virginia.
B) The effects of direct parental control on delinquency among home-schooled boys.
C) The effectiveness of family counseling in reducing child aggression: What works?
D) Tell me who your friend is: High-quality listening increases subjective well-being.