One Study Found That the Short Allele of the Serotonin

One study found that the short allele of the serotonin transporter promoter gene (5-HTTLPR) contributes to increased rates of depression in all girls, but it only affects boys who _____.

A) ruminate
B) are suicidal
C) come from high-socioeconomic-status communities
D) come from low-socioeconomic-status communities