Biological factors are only part of the story of emotion. For example, Juan's caregiver plays a role in his neurobiological regulation. By soothing Juan when he cries and shows distress, the caregiver is helping Juan:

a. know that crying will not help him get attention.
b. increase the production of the stress hormone.
c. modulate his emotions and reduce the level of stress hormones.
d. None of these.