The correct answer is b) abduction.
Abduction is the term used in anatomy to describe the movement of a limb or other body part away from the midline of the body. For instance, when you raise your arms sideways or spread your fingers apart, you are performing abduction. This is essential for multiple movements in daily life and physical activities.
In contrast, adduction would refer to moving a limb towards the midline. Inversion involves the movement of the foot where the sole turns inward, while flexion and extension refer to bending and straightening movements, typically at a joint.