In a Study by Cahill and Colleagues (1994), Researchers Gave

In a study by Cahill and colleagues (1994) , researchers gave half of the participants a drug while the others received a placebo. They found that the drug interfered with memory for details of an emotionally intense story, relative to the placebo, but had no effect on memory for details of a neutral story. What did the drug used in this study do?

A) It blocks the activity of serotonin in the hippocampus.
B) It increases overall physical arousal.
C) It reduces parasympathetic nervous system influence on the heart.
D) It blocks some aspects of sympathetic nervous system activation.