Answer:
A. Serotonin levels are low, and by increasing serotonin, the patient will have an increase in happy feelings.
Explanation:
I calculated it logically
At the shoulder, the head of the humerus articulates with the glenoid fossa of the scapula. More distally, at the elbow, the capitulum of the humerus articulates with the head of the radius, and the trochlea of the humerus articulates with the trochlear notch of the ulna.