Final answer:
Option A. The term for bending joints to decrease the angle between them is flexion. It's seen at synovial joints like the knee, where it's called knee flexion. Extension is the opposite, increasing the angle and straightening the joint.
Step-by-step explanation:
The term that describes bending parts at a joint so that the angle between them decreases and the parts come closer together, such as bending the knee, is called flexion. This action is observed at synovial joints like the joint of the knee, where knee flexion occurs, as well as at the hip, elbow, and fingers. In contrast, extension is the movement that increases the angle between the parts of the joint, straightening them.
Other movements at joints include abduction, which is moving a limb away from the body's midline, and adduction, which brings it closer to the midline. The correct answer is A. Flexion. Flexion is the bending of parts at a joint so that the angle between them decreases and the parts come closer together. This can be seen when bending the knee, bringing the foot toward the posterior thigh.