As Preschoolers, the Children Born to the Women Who Were

As preschoolers, the children born to the women who were diagnosed with both PTSD and depression following the September 11, 2001, attacks on the World Trade Center showed evidence of higher reactivity to stimuli and more aggressive behavior than did children of terrorism-exposed mothers who did not develop these disorders. What is the likely source?

A) the ability of cortisol and other stress hormones to cross the placenta
B) learned behaviors based on the observation of PTSD symptoms in others
C) operant conditioning that rewarded such behaviors among these families
D) the inhibition of serotonin and dopamine during brain development