In 2015, Sorokowski et al. published an article in Personality and Individual Differences about the the relationship between men's selfie posting behavior and narcissism. What was the general conclusion of the authors?

-Narcissism was related to selfie-posting behavior among male adolescents but not among men.

-Narcissism was related to men's selfie-posting behavior on Instagram, but not on Facebook.

-Narcissism was unrelated to selfie-posting behavior.

-Narcissism predicted selfie-posting behavior more strongly among men than women.