Question

the primary movement of a pivot joint is
rotation
abduction
adduction
circumduction
hyperextension

Explanation:

A pivot joint allows rotation around a single axis. Abduction (movement away from mid - line), adduction (movement towards mid - line), circumduction (circular movement combining flexion, extension, abduction and adduction) and hyperextension (extension beyond normal range) are not the primary movements of a pivot joint.

Answer:

rotation