Research by DeYoung suggests that the stability traits (emotional stability, agreeableness, and conscientiousness) are associated with the neurotransmitter and the plasticity traits (extraversion and openness) are associated with the neurotransmitter .

Serotonin, dopamine

Explanation:

Dopamine is a neurotransmitter that plays a role in motivation and reward. When you want to achieve something and you achieve that goal. After achieving that goal you feel satisfied, that satisfaction occurs because of the rush of dopamine. It plays a great role in depression.

Serotonin: Low serotonin does not create depression Increasing serotonin levels by SSRI is a cause of treatment of depression. However, it takes time. There are around 40 to 60 percent of people are suffering from moderate to severe depression.  

the correct answer is a